diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index b36a77d77..fb00b0d0e 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1206,7 +1206,7 @@ Changes
 * Testcase reports with a ``url`` attribute will now properly write this to junitxml.
   Thanks `@fushi`_ for the PR (`#1874`_).
 
-* Remove common items from dict comparision output when verbosity=1. Also update
+* Remove common items from dict comparison output when verbosity=1. Also update
   the truncation message to make it clearer that pytest truncates all
   assertion messages if verbosity < 2 (`#1512`_).
   Thanks `@mattduck`_ for the PR
@@ -1218,7 +1218,7 @@ Changes
 * fix `#2013`_: turn RecordedWarning into ``namedtuple``,
   to give it a comprehensible repr while preventing unwarranted modification.
 
-* fix `#2208`_: ensure a iteration limit for _pytest.compat.get_real_func.
+* fix `#2208`_: ensure an iteration limit for _pytest.compat.get_real_func.
   Thanks `@RonnyPfannschmidt`_ for the report and PR.
 
 * Hooks are now verified after collection is complete, rather than right after loading installed plugins. This
@@ -1322,7 +1322,7 @@ Bug Fixes
   Notably, importing the ``anydbm`` module is fixed. (`#2248`_).
   Thanks `@pfhayes`_ for the PR.
 
-* junitxml: Fix problematic case where system-out tag occured twice per testcase
+* junitxml: Fix problematic case where system-out tag occurred twice per testcase
   element in the XML report. Thanks `@kkoukiou`_ for the PR.
 
 * Fix regression, pytest now skips unittest correctly if run with ``--pdb``
@@ -2918,7 +2918,7 @@ time or change existing behaviors in order to make them less surprising/more use
   "::" node id specifications (copy pasted from "-v" output)
 
 - fix issue544 by only removing "@NUM" at the end of "::" separated parts
-  and if the part has an ".py" extension
+  and if the part has a ".py" extension
 
 - don't use py.std import helper, rather import things directly.
   Thanks Bruno Oliveira.
@@ -3189,7 +3189,7 @@ time or change existing behaviors in order to make them less surprising/more use
 
   would not work correctly because pytest assumes @pytest.mark.some
   gets a function to be decorated already.  We now at least detect if this
-  arg is an lambda and thus the example will work.  Thanks Alex Gaynor
+  arg is a lambda and thus the example will work.  Thanks Alex Gaynor
   for bringing it up.
 
 - xfail a test on pypy that checks wrong encoding/ascii (pypy does
@@ -3502,7 +3502,7 @@ Bug fixes:
   rather use the post-2.0 parametrize features instead of yield, see:
   http://pytest.org/latest/example/parametrize.html
 - fix autouse-issue where autouse-fixtures would not be discovered
-  if defined in a a/conftest.py file and tests in a/tests/test_some.py
+  if defined in an a/conftest.py file and tests in a/tests/test_some.py
 - fix issue226 - LIFO ordering for fixture teardowns
 - fix issue224 - invocations with >256 char arguments now work
 - fix issue91 - add/discuss package/directory level setups in example
@@ -4072,7 +4072,7 @@ Bug fixes:
 - make path.bestrelpath(path) return ".", note that when calling
   X.bestrelpath the assumption is that X is a directory.
 - make initial conftest discovery ignore "--" prefixed arguments
-- fix resultlog plugin when used in an multicpu/multihost xdist situation
+- fix resultlog plugin when used in a multicpu/multihost xdist situation
   (thanks Jakub Gustak)
 - perform distributed testing related reporting in the xdist-plugin
   rather than having dist-related code in the generic py.test
diff --git a/_pytest/_code/source.py b/_pytest/_code/source.py
index cb5e13f05..6c2856ea8 100644
--- a/_pytest/_code/source.py
+++ b/_pytest/_code/source.py
@@ -14,7 +14,7 @@ cpy_compile = compile
 
 
 class Source(object):
-    """ a immutable object holding a source code fragment,
+    """ an immutable object holding a source code fragment,
         possibly deindenting it.
     """
     _compilecounter = 0
diff --git a/_pytest/capture.py b/_pytest/capture.py
index 9f4f41c41..d71f59ac2 100644
--- a/_pytest/capture.py
+++ b/_pytest/capture.py
@@ -315,7 +315,7 @@ class CaptureFixture(object):
 
 
 def safe_text_dupfile(f, mode, default_encoding="UTF8"):
-    """ return a open text file object that's a duplicate of f on the
+    """ return an open text file object that's a duplicate of f on the
         FD-level if possible.
     """
     encoding = getattr(f, "encoding", None)
diff --git a/_pytest/compat.py b/_pytest/compat.py
index a5fa03719..e5c8c3940 100644
--- a/_pytest/compat.py
+++ b/_pytest/compat.py
@@ -257,7 +257,7 @@ def safe_getattr(object, name, default):
 
 
 def _is_unittest_unexpected_success_a_failure():
-    """Return if the test suite should fail if a @expectedFailure unittest test PASSES.
+    """Return if the test suite should fail if an @expectedFailure unittest test PASSES.
 
     From https://docs.python.org/3/library/unittest.html?highlight=unittest#unittest.TestResult.wasSuccessful:
         Changed in version 3.4: Returns False if there were any
diff --git a/_pytest/doctest.py b/_pytest/doctest.py
index 131109cba..4511f5889 100644
--- a/_pytest/doctest.py
+++ b/_pytest/doctest.py
@@ -24,7 +24,7 @@ DOCTEST_REPORT_CHOICES = (
     DOCTEST_REPORT_CHOICE_ONLY_FIRST_FAILURE,
 )
 
-# Lazy definiton of runner class
+# Lazy definition of runner class
 RUNNER_CLASS = None
 
 
diff --git a/_pytest/fixtures.py b/_pytest/fixtures.py
index 2ac340e6f..dbefbab71 100644
--- a/_pytest/fixtures.py
+++ b/_pytest/fixtures.py
@@ -290,7 +290,7 @@ class FixtureRequest(FuncargnamesCompatAttr):
     def _getnextfixturedef(self, argname):
         fixturedefs = self._arg2fixturedefs.get(argname, None)
         if fixturedefs is None:
-            # we arrive here because of a  a dynamic call to
+            # we arrive here because of a dynamic call to
             # getfixturevalue(argname) usage which was naturally
             # not known at parsing/collection time
             parentid = self._pyfuncitem.parent.nodeid
@@ -1026,7 +1026,7 @@ class FixtureManager(object):
     def getfixtureclosure(self, fixturenames, parentnode):
         # collect the closure of all fixtures , starting with the given
         # fixturenames as the initial set.  As we have to visit all
-        # factory definitions anyway, we also return a arg2fixturedefs
+        # factory definitions anyway, we also return an arg2fixturedefs
         # mapping so that the caller can reuse it and does not have
         # to re-discover fixturedefs again for each fixturename
         # (discovering matching fixtures for a given name/node is expensive)
diff --git a/_pytest/main.py b/_pytest/main.py
index 03db67b60..6c4bd65bb 100644
--- a/_pytest/main.py
+++ b/_pytest/main.py
@@ -90,7 +90,7 @@ def pytest_addoption(parser):
 
 
 def pytest_configure(config):
-    __import__('pytest').config = config  # compatibiltiy
+    __import__('pytest').config = config  # compatibility
 
 
 def wrap_session(config, doit):
@@ -290,7 +290,7 @@ class Interrupted(KeyboardInterrupt):
 
 
 class Failed(Exception):
-    """ signals an stop as failed test run. """
+    """ signals a stop as failed test run. """
 
 
 class Session(nodes.FSCollector):
diff --git a/_pytest/mark/structures.py b/_pytest/mark/structures.py
index a0d4a5ce7..24c4880cd 100644
--- a/_pytest/mark/structures.py
+++ b/_pytest/mark/structures.py
@@ -204,7 +204,7 @@ class MarkDecorator(object):
 
 def get_unpacked_marks(obj):
     """
-    obtain the unpacked marks that are stored on a object
+    obtain the unpacked marks that are stored on an object
     """
     mark_list = getattr(obj, 'pytestmark', [])
 
@@ -217,7 +217,7 @@ def get_unpacked_marks(obj):
 
 
 def store_mark(obj, mark):
-    """store a Mark on a object
+    """store a Mark on an object
     this is used to implement the Mark declarations/decorators correctly
     """
     assert isinstance(mark, Mark), mark
diff --git a/_pytest/outcomes.py b/_pytest/outcomes.py
index 7f0c18fa6..640c5773a 100644
--- a/_pytest/outcomes.py
+++ b/_pytest/outcomes.py
@@ -83,7 +83,7 @@ skip.Exception = Skipped
 
 
 def fail(msg="", pytrace=True):
-    """ explicitly fail an currently-executing test with the given Message.
+    """ explicitly fail a currently-executing test with the given Message.
 
     :arg pytrace: if false the msg represents the full failure information
                   and no python traceback will be reported.
diff --git a/_pytest/python.py b/_pytest/python.py
index 4c0340d6e..dd27de504 100644
--- a/_pytest/python.py
+++ b/_pytest/python.py
@@ -55,7 +55,7 @@ def filter_traceback(entry):
     is_generated = '<' in raw_filename and '>' in raw_filename
     if is_generated:
         return False
-    # entry.path might point to an non-existing file, in which case it will
+    # entry.path might point to a non-existing file, in which case it will
     # also return a str object. see #1133
     p = py.path.local(entry.path)
     return not p.relto(_pluggy_dir) and not p.relto(_pytest_dir) and not p.relto(_py_dir)
diff --git a/doc/en/announce/release-2.3.4.rst b/doc/en/announce/release-2.3.4.rst
index d6c597b54..fc5f361d5 100644
--- a/doc/en/announce/release-2.3.4.rst
+++ b/doc/en/announce/release-2.3.4.rst
@@ -18,7 +18,7 @@ comes with the following fixes and features:
   rather use the post-2.0 parametrize features instead of yield, see:
   http://pytest.org/latest/example/parametrize.html
 - fix autouse-issue where autouse-fixtures would not be discovered
-  if defined in a a/conftest.py file and tests in a/tests/test_some.py
+  if defined in an a/conftest.py file and tests in a/tests/test_some.py
 - fix issue226 - LIFO ordering for fixture teardowns
 - fix issue224 - invocations with >256 char arguments now work
 - fix issue91 - add/discuss package/directory level setups in example
diff --git a/doc/en/announce/release-2.6.1.rst b/doc/en/announce/release-2.6.1.rst
index 6f27c5861..2f3257cd8 100644
--- a/doc/en/announce/release-2.6.1.rst
+++ b/doc/en/announce/release-2.6.1.rst
@@ -52,7 +52,7 @@ Changes 2.6.1
   "::" node id specifications (copy pasted from "-v" output)
 
 - fix issue544 by only removing "@NUM" at the end of "::" separated parts
-  and if the part has an ".py" extension
+  and if the part has a ".py" extension
 
 - don't use py.std import helper, rather import things directly.
   Thanks Bruno Oliveira.
diff --git a/doc/en/example/parametrize.rst b/doc/en/example/parametrize.rst
index 073f7fb88..2cf3fa1e4 100644
--- a/doc/en/example/parametrize.rst
+++ b/doc/en/example/parametrize.rst
@@ -469,7 +469,7 @@ If you run this with reporting for skips enabled::
     
     =================== 1 passed, 1 skipped in 0.12 seconds ====================
 
-You'll see that we don't have a ``opt2`` module and thus the second test run
+You'll see that we don't have an ``opt2`` module and thus the second test run
 of our ``test_func1`` was skipped.  A few notes:
 
 - the fixture functions in the ``conftest.py`` file are "session-scoped" because we
diff --git a/doc/en/goodpractices.rst b/doc/en/goodpractices.rst
index 490ecadd6..d9f0fff11 100644
--- a/doc/en/goodpractices.rst
+++ b/doc/en/goodpractices.rst
@@ -145,7 +145,7 @@ Note that this layout also works in conjunction with the ``src`` layout mentione
 
 .. note::
 
-    If ``pytest`` finds a "a/b/test_module.py" test file while
+    If ``pytest`` finds an "a/b/test_module.py" test file while
     recursing into the filesystem it determines the import name
     as follows:
 
diff --git a/doc/en/reference.rst b/doc/en/reference.rst
index ef7f8f51f..a5a114bf1 100644
--- a/doc/en/reference.rst
+++ b/doc/en/reference.rst
@@ -933,8 +933,8 @@ passed multiple times. The expected format is ``name=value``. For example::
 
     Allows to pick the action for empty parametersets in parameterization
 
-    * ``skip`` skips tests with a empty parameterset (default)
-    * ``xfail`` marks tests with a empty parameterset as xfail(run=False)
+    * ``skip`` skips tests with an empty parameterset (default)
+    * ``xfail`` marks tests with an empty parameterset as xfail(run=False)
 
     .. code-block:: ini
 
diff --git a/testing/code/test_excinfo.py b/testing/code/test_excinfo.py
index 6b4adf001..8fd59423f 100644
--- a/testing/code/test_excinfo.py
+++ b/testing/code/test_excinfo.py
@@ -1198,7 +1198,7 @@ def test_cwd_deleted(testdir):
 def test_exception_repr_extraction_error_on_recursion():
     """
     Ensure we can properly detect a recursion error even
-    if some locals raise error on comparision (#2459).
+    if some locals raise error on comparison (#2459).
     """
     class numpy_like(object):
 
diff --git a/testing/python/fixture.py b/testing/python/fixture.py
index 10eb00602..1e37d78d9 100644
--- a/testing/python/fixture.py
+++ b/testing/python/fixture.py
@@ -1553,7 +1553,7 @@ class TestAutouseDiscovery(object):
 
     def test_callables_nocode(self, testdir):
         """
-        a imported mock.call would break setup/factory discovery
+        an imported mock.call would break setup/factory discovery
         due to it being callable and __code__ not being a code object
         """
         testdir.makepyfile("""
diff --git a/testing/test_assertion.py b/testing/test_assertion.py
index 341090580..51229d3e1 100644
--- a/testing/test_assertion.py
+++ b/testing/test_assertion.py
@@ -473,7 +473,7 @@ class TestAssert_reprcompare(object):
     def test_one_repr_empty(self):
         """
         the faulty empty string repr did trigger
-        a unbound local error in _diff_text
+        an unbound local error in _diff_text
         """
         class A(str):
             def __repr__(self):
diff --git a/testing/test_capture.py b/testing/test_capture.py
index 7fccc055d..bc8ae6534 100644
--- a/testing/test_capture.py
+++ b/testing/test_capture.py
@@ -998,7 +998,7 @@ class TestStdCapture(object):
                         reason='text output different for bytes on python3')
     def test_capturing_readouterr_decode_error_handling(self):
         with self.getcapture() as cap:
-            # triggered a internal error in pytest
+            # triggered an internal error in pytest
             print('\xa6')
             out, err = cap.readouterr()
         assert out == py.builtin._totext('\ufffd\n', 'unicode-escape')
diff --git a/testing/test_conftest.py b/testing/test_conftest.py
index 6566f752a..93bf8ea8d 100644
--- a/testing/test_conftest.py
+++ b/testing/test_conftest.py
@@ -373,7 +373,7 @@ class TestConftestVisibility(object):
     (None, 1, 1),
 ])
 def test_search_conftest_up_to_inifile(testdir, confcutdir, passed, error):
-    """Test that conftest files are detected only up to a ini file, unless
+    """Test that conftest files are detected only up to an ini file, unless
     an explicit --confcutdir option is given.
     """
     root = testdir.tmpdir
diff --git a/testing/test_nose.py b/testing/test_nose.py
index df3e1a94b..1964b06c5 100644
--- a/testing/test_nose.py
+++ b/testing/test_nose.py
@@ -289,7 +289,7 @@ def test_nose_setup_ordering(testdir):
 
 
 def test_apiwrapper_problem_issue260(testdir):
-    # this would end up trying a call a optional teardown on the class
+    # this would end up trying a call an optional teardown on the class
     # for plain unittests we dont want nose behaviour
     testdir.makepyfile("""
         import unittest