diff --git a/django/contrib/auth/decorators.py b/django/contrib/auth/decorators.py
index 4d62aec93a03..3407555852e1 100644
--- a/django/contrib/auth/decorators.py
+++ b/django/contrib/auth/decorators.py
@@ -1,7 +1,8 @@
 from functools import wraps
+from inspect import iscoroutinefunction
 from urllib.parse import urlsplit
 
-from asgiref.sync import async_to_sync, iscoroutinefunction, sync_to_async
+from asgiref.sync import async_to_sync, sync_to_async
 
 from django.conf import settings
 from django.contrib.auth import REDIRECT_FIELD_NAME
diff --git a/django/contrib/auth/middleware.py b/django/contrib/auth/middleware.py
index bd8a1c108084..a28e1705a378 100644
--- a/django/contrib/auth/middleware.py
+++ b/django/contrib/auth/middleware.py
@@ -1,8 +1,7 @@
 from functools import partial
+from inspect import iscoroutinefunction, markcoroutinefunction
 from urllib.parse import urlsplit
 
-from asgiref.sync import iscoroutinefunction, markcoroutinefunction
-
 from django.conf import settings
 from django.contrib import auth
 from django.contrib.auth import REDIRECT_FIELD_NAME, load_backend
diff --git a/django/core/handlers/base.py b/django/core/handlers/base.py
index af3e0c3a504e..d65a5edcb6a6 100644
--- a/django/core/handlers/base.py
+++ b/django/core/handlers/base.py
@@ -1,8 +1,9 @@
 import asyncio
 import logging
 import types
+from inspect import iscoroutinefunction
 
-from asgiref.sync import async_to_sync, iscoroutinefunction, sync_to_async
+from asgiref.sync import async_to_sync, sync_to_async
 
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured, MiddlewareNotUsed
diff --git a/django/core/handlers/exception.py b/django/core/handlers/exception.py
index 1243734705e8..4adc9d7c6af2 100644
--- a/django/core/handlers/exception.py
+++ b/django/core/handlers/exception.py
@@ -1,8 +1,9 @@
 import logging
 import sys
 from functools import wraps
+from inspect import iscoroutinefunction
 
-from asgiref.sync import iscoroutinefunction, sync_to_async
+from asgiref.sync import sync_to_async
 
 from django.conf import settings
 from django.core import signals
diff --git a/django/core/paginator.py b/django/core/paginator.py
index aabc2f85321b..d1842d6adb67 100644
--- a/django/core/paginator.py
+++ b/django/core/paginator.py
@@ -3,7 +3,7 @@
 import warnings
 from math import ceil
 
-from asgiref.sync import iscoroutinefunction, sync_to_async
+from asgiref.sync import sync_to_async
 
 from django.utils.deprecation import RemovedInDjango70Warning
 from django.utils.functional import cached_property
@@ -266,7 +266,7 @@ async def acount(self):
             return self._cache_acount
         c = getattr(self.object_list, "acount", None)
         if (
-            iscoroutinefunction(c)
+            inspect.iscoroutinefunction(c)
             and not inspect.isbuiltin(c)
             and method_has_no_args(c)
         ):
diff --git a/django/dispatch/dispatcher.py b/django/dispatch/dispatcher.py
index 21d77bd88429..d4a6eff2bcf1 100644
--- a/django/dispatch/dispatcher.py
+++ b/django/dispatch/dispatcher.py
@@ -3,8 +3,9 @@
 import logging
 import threading
 import weakref
+from inspect import iscoroutinefunction
 
-from asgiref.sync import async_to_sync, iscoroutinefunction, sync_to_async
+from asgiref.sync import async_to_sync, sync_to_async
 
 from django.utils.inspect import func_accepts_kwargs
 
diff --git a/django/test/testcases.py b/django/test/testcases.py
index c56fa52806ea..5f83612fe532 100644
--- a/django/test/testcases.py
+++ b/django/test/testcases.py
@@ -11,6 +11,7 @@
 from copy import copy, deepcopy
 from difflib import get_close_matches
 from functools import wraps
+from inspect import iscoroutinefunction
 from unittest import mock
 from unittest.suite import _DebugResult
 from unittest.util import safe_repr
@@ -25,7 +26,7 @@
 )
 from urllib.request import url2pathname
 
-from asgiref.sync import async_to_sync, iscoroutinefunction
+from asgiref.sync import async_to_sync
 
 from django.apps import apps
 from django.conf import settings
diff --git a/django/test/utils.py b/django/test/utils.py
index 3661010463d5..ec888b358882 100644
--- a/django/test/utils.py
+++ b/django/test/utils.py
@@ -8,14 +8,13 @@
 import warnings
 from contextlib import contextmanager
 from functools import wraps
+from inspect import iscoroutinefunction
 from io import StringIO
 from itertools import chain
 from types import SimpleNamespace
 from unittest import TestCase, skipIf, skipUnless
 from xml.dom.minidom import Node, parseString
 
-from asgiref.sync import iscoroutinefunction
-
 from django.apps import apps
 from django.apps.registry import Apps
 from django.conf import UserSettingsHolder, settings
diff --git a/django/utils/decorators.py b/django/utils/decorators.py
index 83586dfc2cc9..7e4d724b462e 100644
--- a/django/utils/decorators.py
+++ b/django/utils/decorators.py
@@ -1,8 +1,7 @@
 "Functions that help with dynamically creating decorators for views."
 
 from functools import partial, update_wrapper, wraps
-
-from asgiref.sync import iscoroutinefunction, markcoroutinefunction
+from inspect import iscoroutinefunction, markcoroutinefunction
 
 
 class classonlymethod(classmethod):
diff --git a/django/utils/deprecation.py b/django/utils/deprecation.py
index b10fb58c6545..6b017cd91731 100644
--- a/django/utils/deprecation.py
+++ b/django/utils/deprecation.py
@@ -3,8 +3,9 @@
 import os
 import warnings
 from collections import Counter
+from inspect import iscoroutinefunction, markcoroutinefunction
 
-from asgiref.sync import iscoroutinefunction, markcoroutinefunction, sync_to_async
+from asgiref.sync import sync_to_async
 
 import django
 
diff --git a/django/views/decorators/cache.py b/django/views/decorators/cache.py
index aa1679baff1c..f08d30846c2b 100644
--- a/django/views/decorators/cache.py
+++ b/django/views/decorators/cache.py
@@ -1,6 +1,5 @@
 from functools import wraps
-
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.middleware.cache import CacheMiddleware
 from django.utils.cache import add_never_cache_headers, patch_cache_control
diff --git a/django/views/decorators/clickjacking.py b/django/views/decorators/clickjacking.py
index c20fa59d2a29..105f0ed11a62 100644
--- a/django/views/decorators/clickjacking.py
+++ b/django/views/decorators/clickjacking.py
@@ -1,6 +1,5 @@
 from functools import wraps
-
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 
 def xframe_options_deny(view_func):
diff --git a/django/views/decorators/common.py b/django/views/decorators/common.py
index d09b0bfee47d..d4e9a1888e51 100644
--- a/django/views/decorators/common.py
+++ b/django/views/decorators/common.py
@@ -1,6 +1,5 @@
 from functools import wraps
-
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 
 def no_append_slash(view_func):
diff --git a/django/views/decorators/csp.py b/django/views/decorators/csp.py
index 9033d9cdf0ee..1c537fe1f2c5 100644
--- a/django/views/decorators/csp.py
+++ b/django/views/decorators/csp.py
@@ -1,6 +1,5 @@
 from functools import wraps
-
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 
 def _make_csp_decorator(config_attr_name, config_attr_value):
diff --git a/django/views/decorators/csrf.py b/django/views/decorators/csrf.py
index 64c478b42ef4..9f13114580c3 100644
--- a/django/views/decorators/csrf.py
+++ b/django/views/decorators/csrf.py
@@ -1,6 +1,5 @@
 from functools import wraps
-
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.middleware.csrf import CsrfViewMiddleware, get_token
 from django.utils.decorators import decorator_from_middleware
diff --git a/django/views/decorators/debug.py b/django/views/decorators/debug.py
index 506aaeb64d2b..38ccef4c92ce 100644
--- a/django/views/decorators/debug.py
+++ b/django/views/decorators/debug.py
@@ -1,7 +1,6 @@
 import inspect
 from functools import wraps
-
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.http import HttpRequest
 
diff --git a/django/views/decorators/http.py b/django/views/decorators/http.py
index 408039937cbd..3bafa880b652 100644
--- a/django/views/decorators/http.py
+++ b/django/views/decorators/http.py
@@ -4,8 +4,7 @@
 
 import datetime
 from functools import wraps
-
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.http import HttpResponseNotAllowed
 from django.middleware.http import ConditionalGetMiddleware
diff --git a/django/views/decorators/vary.py b/django/views/decorators/vary.py
index 9beab8b4db84..b4c467a8807a 100644
--- a/django/views/decorators/vary.py
+++ b/django/views/decorators/vary.py
@@ -1,6 +1,5 @@
 from functools import wraps
-
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.utils.cache import patch_vary_headers
 
diff --git a/django/views/generic/base.py b/django/views/generic/base.py
index a961dfddee55..649d871cf738 100644
--- a/django/views/generic/base.py
+++ b/django/views/generic/base.py
@@ -1,8 +1,7 @@
 import logging
+from inspect import iscoroutinefunction, markcoroutinefunction
 from urllib.parse import urlparse
 
-from asgiref.sync import iscoroutinefunction, markcoroutinefunction
-
 from django.core.exceptions import ImproperlyConfigured
 from django.http import (
     HttpResponse,
diff --git a/docs/topics/async.txt b/docs/topics/async.txt
index 5cf9fd46242a..2607381ad274 100644
--- a/docs/topics/async.txt
+++ b/docs/topics/async.txt
@@ -28,9 +28,9 @@ class-based view, this means declaring the HTTP method handlers, such as
 
 .. note::
 
-    Django uses ``asgiref.sync.iscoroutinefunction`` to test if your view is
+    Django uses ``inspect.iscoroutinefunction`` to test if your view is
     asynchronous or not. If you implement your own method of returning a
-    coroutine, ensure you use ``asgiref.sync.markcoroutinefunction`` so this
+    coroutine, ensure you use ``inspect.markcoroutinefunction`` so this
     function returns ``True``.
 
 Under a WSGI server, async views will run in their own, one-off event loop.
diff --git a/docs/topics/http/middleware.txt b/docs/topics/http/middleware.txt
index 1c3b3c2a26cd..8bca89f56de6 100644
--- a/docs/topics/http/middleware.txt
+++ b/docs/topics/http/middleware.txt
@@ -318,7 +318,7 @@ If your middleware has both ``sync_capable = True`` and
 ``async_capable = True``, then Django will pass it the request without
 converting it. In this case, you can work out if your middleware will receive
 async requests by checking if the ``get_response`` object you are passed is a
-coroutine function, using ``asgiref.sync.iscoroutinefunction``.
+coroutine function, using ``inspect.iscoroutinefunction``.
 
 The ``django.utils.decorators`` module contains
 :func:`~django.utils.decorators.sync_only_middleware`,
@@ -337,7 +337,7 @@ at an additional performance penalty.
 
 Here's an example of how to create a middleware function that supports both::
 
-    from asgiref.sync import iscoroutinefunction
+    from inspect import iscoroutinefunction
     from django.utils.decorators import sync_and_async_middleware
 
 
@@ -373,7 +373,7 @@ Here's an example of how to create a middleware function that supports both::
 When using an asynchronous class-based middleware, you must ensure that
 instances are correctly marked as coroutine functions::
 
-    from asgiref.sync import iscoroutinefunction, markcoroutinefunction
+    from inspect import iscoroutinefunction, markcoroutinefunction
 
 
     class AsyncMiddleware:
diff --git a/tests/admin_changelist/tests.py b/tests/admin_changelist/tests.py
index e0772a3e6d4a..330859bcf438 100644
--- a/tests/admin_changelist/tests.py
+++ b/tests/admin_changelist/tests.py
@@ -914,6 +914,7 @@ def test_exact_lookup_with_more_lenient_formfield(self):
         cl = m.get_changelist_instance(request)
         self.assertCountEqual(cl.queryset, [obj])
 
+    @skipUnlessDBFeature("supports_primitives_in_json_field")
     def test_exact_lookup_validates_each_field_independently(self):
         """
         Each field validates the search term independently without leaking
diff --git a/tests/async/tests.py b/tests/async/tests.py
index 6ca5c989b06c..43051c369a4b 100644
--- a/tests/async/tests.py
+++ b/tests/async/tests.py
@@ -1,8 +1,9 @@
 import asyncio
 import os
+from inspect import iscoroutinefunction
 from unittest import mock
 
-from asgiref.sync import async_to_sync, iscoroutinefunction
+from asgiref.sync import async_to_sync
 
 from django.core.cache import DEFAULT_CACHE_ALIAS, caches
 from django.core.exceptions import ImproperlyConfigured, SynchronousOnlyOperation
diff --git a/tests/auth_tests/test_decorators.py b/tests/auth_tests/test_decorators.py
index 2c3f93d2abf8..08f6186e34eb 100644
--- a/tests/auth_tests/test_decorators.py
+++ b/tests/auth_tests/test_decorators.py
@@ -1,4 +1,4 @@
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.conf import settings
 from django.contrib.auth import models
diff --git a/tests/decorators/test_cache.py b/tests/decorators/test_cache.py
index 513ff7e7114e..1aca6967e0b6 100644
--- a/tests/decorators/test_cache.py
+++ b/tests/decorators/test_cache.py
@@ -1,7 +1,6 @@
+from inspect import iscoroutinefunction
 from unittest import mock
 
-from asgiref.sync import iscoroutinefunction
-
 from django.http import HttpRequest, HttpResponse
 from django.test import SimpleTestCase
 from django.utils.decorators import method_decorator
diff --git a/tests/decorators/test_clickjacking.py b/tests/decorators/test_clickjacking.py
index fe4c551648d9..b585b00451ac 100644
--- a/tests/decorators/test_clickjacking.py
+++ b/tests/decorators/test_clickjacking.py
@@ -1,4 +1,4 @@
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.http import HttpRequest, HttpResponse
 from django.middleware.clickjacking import XFrameOptionsMiddleware
diff --git a/tests/decorators/test_common.py b/tests/decorators/test_common.py
index a2661ef30a13..53ec5c07bcd1 100644
--- a/tests/decorators/test_common.py
+++ b/tests/decorators/test_common.py
@@ -1,4 +1,4 @@
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.http import HttpRequest, HttpResponse
 from django.test import SimpleTestCase
diff --git a/tests/decorators/test_csp.py b/tests/decorators/test_csp.py
index 2def6b0f79cb..46e573cfa1b6 100644
--- a/tests/decorators/test_csp.py
+++ b/tests/decorators/test_csp.py
@@ -1,7 +1,6 @@
+from inspect import iscoroutinefunction
 from itertools import product
 
-from asgiref.sync import iscoroutinefunction
-
 from django.http import HttpRequest, HttpResponse
 from django.test import SimpleTestCase
 from django.utils.csp import CSP
diff --git a/tests/decorators/test_csrf.py b/tests/decorators/test_csrf.py
index c1934448643f..eb01339cf950 100644
--- a/tests/decorators/test_csrf.py
+++ b/tests/decorators/test_csrf.py
@@ -1,4 +1,4 @@
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.conf import settings
 from django.http import HttpRequest, HttpResponse
diff --git a/tests/decorators/test_gzip.py b/tests/decorators/test_gzip.py
index 87eff0fe7772..2d64c171f70e 100644
--- a/tests/decorators/test_gzip.py
+++ b/tests/decorators/test_gzip.py
@@ -1,4 +1,4 @@
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.http import HttpRequest, HttpResponse
 from django.test import SimpleTestCase
diff --git a/tests/decorators/test_http.py b/tests/decorators/test_http.py
index 4b1b81588e21..b0bb4c1e00fb 100644
--- a/tests/decorators/test_http.py
+++ b/tests/decorators/test_http.py
@@ -1,6 +1,5 @@
 import datetime
-
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.http import HttpRequest, HttpResponse, HttpResponseNotAllowed
 from django.test import SimpleTestCase
diff --git a/tests/decorators/test_vary.py b/tests/decorators/test_vary.py
index ccab18a6609b..cf5f36b97dc6 100644
--- a/tests/decorators/test_vary.py
+++ b/tests/decorators/test_vary.py
@@ -1,4 +1,4 @@
-from asgiref.sync import iscoroutinefunction
+from inspect import iscoroutinefunction
 
 from django.http import HttpRequest, HttpResponse
 from django.test import SimpleTestCase
diff --git a/tests/decorators/tests.py b/tests/decorators/tests.py
index fce64a8834aa..0c5213f0abbe 100644
--- a/tests/decorators/tests.py
+++ b/tests/decorators/tests.py
@@ -1,9 +1,8 @@
 import asyncio
 from functools import update_wrapper, wraps
+from inspect import iscoroutinefunction
 from unittest import TestCase
 
-from asgiref.sync import iscoroutinefunction
-
 from django.contrib.admin.views.decorators import staff_member_required
 from django.contrib.auth.decorators import (
     login_required,
diff --git a/tests/middleware_exceptions/middleware.py b/tests/middleware_exceptions/middleware.py
index f50aa61327e6..9d4c87099fb6 100644
--- a/tests/middleware_exceptions/middleware.py
+++ b/tests/middleware_exceptions/middleware.py
@@ -1,4 +1,4 @@
-from asgiref.sync import iscoroutinefunction, markcoroutinefunction
+from inspect import iscoroutinefunction, markcoroutinefunction
 
 from django.http import Http404, HttpResponse
 from django.template import engines
diff --git a/tests/schema/tests.py b/tests/schema/tests.py
index cbc5f57eb91f..024e68f2b36d 100644
--- a/tests/schema/tests.py
+++ b/tests/schema/tests.py
@@ -3805,8 +3805,14 @@ def test_func_unique_constraint_nondeterministic(self):
             with self.assertRaises(DatabaseError):
                 editor.add_constraint(Author, constraint)
 
-    @skipUnlessDBFeature("supports_nulls_distinct_unique_constraints")
+    @skipUnlessDBFeature(
+        "supports_expression_indexes", "supports_nulls_distinct_unique_constraints"
+    )
     def test_unique_constraint_index_nulls_distinct(self):
+        """
+        For a UniqueConstraint with expressions, the backend executes:
+        CREATE UNIQUE INDEX ...
+        """
         with connection.schema_editor() as editor:
             editor.create_model(Author)
         nulls_distinct = UniqueConstraint(
@@ -3831,6 +3837,10 @@ def test_unique_constraint_index_nulls_distinct(self):
 
     @skipUnlessDBFeature("supports_nulls_distinct_unique_constraints")
     def test_unique_constraint_nulls_distinct(self):
+        """
+        For UniqueConstraint(fields=...), the backend executes:
+        ALTER TABLE "schema_author" ADD CONSTRAINT ...
+        """
         with connection.schema_editor() as editor:
             editor.create_model(Author)
         constraint = UniqueConstraint(
diff --git a/tests/signals/tests.py b/tests/signals/tests.py
index 907612459af6..e304424eb8af 100644
--- a/tests/signals/tests.py
+++ b/tests/signals/tests.py
@@ -1,8 +1,7 @@
 import contextvars
+from inspect import markcoroutinefunction
 from unittest import mock
 
-from asgiref.sync import markcoroutinefunction
-
 from django import dispatch
 from django.apps.registry import Apps
 from django.db import models