diff --git a/homeassistant/components/bmw_connected_drive/services.yaml b/homeassistant/components/bmw_connected_drive/services.yaml
index 3c180271919..b9605429a8e 100644
--- a/homeassistant/components/bmw_connected_drive/services.yaml
+++ b/homeassistant/components/bmw_connected_drive/services.yaml
@@ -27,7 +27,7 @@ activate_air_conditioning:
   description: >
     Start the air conditioning of the vehicle. What exactly is started here
     depends on the type of vehicle. It might range from just ventilation over
-    auxilary heating to real air conditioning. The vehicle is identified via
+    auxiliary heating to real air conditioning. The vehicle is identified via
     the vin (see below).
   fields:
     vin:
@@ -39,4 +39,4 @@ update_state:
   description: >
     Fetch the last state of the vehicles of all your accounts from the BMW
     server. This does *not* trigger an update from the vehicle, it just gets
-    the data from the BMW servers. This service does not require any attributes.
\ No newline at end of file
+    the data from the BMW servers. This service does not require any attributes.
diff --git a/homeassistant/components/hassio/handler.py b/homeassistant/components/hassio/handler.py
index a954aaccbd4..c3caf40ba62 100644
--- a/homeassistant/components/hassio/handler.py
+++ b/homeassistant/components/hassio/handler.py
@@ -33,7 +33,7 @@ def _api_bool(funct):
 
 
 def _api_data(funct):
-    """Return a api data."""
+    """Return data of an api."""
     @asyncio.coroutine
     def _wrapper(*argv, **kwargs):
         """Wrap function."""
diff --git a/homeassistant/components/homekit/util.py b/homeassistant/components/homekit/util.py
index c201d884a75..5ddef534202 100644
--- a/homeassistant/components/homekit/util.py
+++ b/homeassistant/components/homekit/util.py
@@ -21,7 +21,7 @@ def validate_entity_config(values):
         params = {}
         if not isinstance(config, dict):
             raise vol.Invalid('The configuration for "{}" must be '
-                              ' an dictionary.'.format(entity))
+                              ' a dictionary.'.format(entity))
 
         for key in (CONF_NAME, ):
             value = config.get(key, -1)
diff --git a/homeassistant/components/insteon_plm/services.yaml b/homeassistant/components/insteon_plm/services.yaml
index a0e250fef1f..9ea53c10fbf 100644
--- a/homeassistant/components/insteon_plm/services.yaml
+++ b/homeassistant/components/insteon_plm/services.yaml
@@ -14,7 +14,7 @@ delete_all_link:
       description: All-Link group number.
       example: 1
 load_all_link_database:
-  description: Load the All-Link Database for a device. WARNING - Loading a device All-LInk database is very time consuming and inconsistant. This may take a LONG time and may need to be repeated to obtain all records.
+  description: Load the All-Link Database for a device. WARNING - Loading a device All-LInk database is very time consuming and inconsistent. This may take a LONG time and may need to be repeated to obtain all records.
   fields:
     entity_id:
       description: Name of the device to print
diff --git a/homeassistant/components/media_player/yamaha.py b/homeassistant/components/media_player/yamaha.py
index 5b8ac2ad236..bb7942a2545 100644
--- a/homeassistant/components/media_player/yamaha.py
+++ b/homeassistant/components/media_player/yamaha.py
@@ -222,7 +222,7 @@ class YamahaDevice(MediaPlayerDevice):
 
     @property
     def zone_id(self):
-        """Return an zone_id to ensure 1 media player per zone."""
+        """Return a zone_id to ensure 1 media player per zone."""
         return '{0}:{1}'.format(self.receiver.ctrl_url, self._zone)
 
     @property
diff --git a/homeassistant/components/sensor/buienradar.py b/homeassistant/components/sensor/buienradar.py
index 6eb67f7cbd8..590d5a8f1ce 100644
--- a/homeassistant/components/sensor/buienradar.py
+++ b/homeassistant/components/sensor/buienradar.py
@@ -197,7 +197,7 @@ class BrSensor(Entity):
 
     def uid(self, coordinates):
         """Generate a unique id using coordinates and sensor type."""
-        # The combination of the location, name an sensor type is unique
+        # The combination of the location, name and sensor type is unique
         return "%2.6f%2.6f%s" % (coordinates[CONF_LATITUDE],
                                  coordinates[CONF_LONGITUDE],
                                  self.type)
diff --git a/homeassistant/components/sensor/hive.py b/homeassistant/components/sensor/hive.py
index 8f8ce2d1681..82816c83404 100644
--- a/homeassistant/components/sensor/hive.py
+++ b/homeassistant/components/sensor/hive.py
@@ -70,7 +70,7 @@ class HiveSensorEntity(Entity):
         return DEVICETYPE_ICONS.get(self.device_type)
 
     def update(self):
-        """Update all Node data frome Hive."""
+        """Update all Node data from Hive."""
         if self.session.core.update_data(self.node_id):
             for entity in self.session.entities:
                 entity.handle_update(self.data_updatesource)
diff --git a/homeassistant/components/sensor/statistics.py b/homeassistant/components/sensor/statistics.py
index 7b2ae537d4b..a77509c18d4 100644
--- a/homeassistant/components/sensor/statistics.py
+++ b/homeassistant/components/sensor/statistics.py
@@ -156,7 +156,7 @@ class StatisticsSensor(Entity):
                 ATTR_CHANGE: self.change,
                 ATTR_AVERAGE_CHANGE: self.average_change,
             }
-            # Only return min/max age if we have a age span
+            # Only return min/max age if we have an age span
             if self._max_age:
                 state.update({
                     ATTR_MAX_AGE: self.max_age,
diff --git a/homeassistant/components/switch/tahoma.py b/homeassistant/components/switch/tahoma.py
index 339a0c39386..aa3554a494c 100644
--- a/homeassistant/components/switch/tahoma.py
+++ b/homeassistant/components/switch/tahoma.py
@@ -1,7 +1,7 @@
 """
 Support for Tahoma Switch - those are push buttons for garage door etc.
 
-Those buttons are implemented as switchs that are never on. They only
+Those buttons are implemented as switches that are never on. They only
 receive the turn_on action, perform the relay click, and stay in OFF state
 
 For more details about this platform, please refer to the documentation at
@@ -19,7 +19,7 @@ _LOGGER = logging.getLogger(__name__)
 
 
 def setup_platform(hass, config, add_devices, discovery_info=None):
-    """Set up Tahoma switchs."""
+    """Set up Tahoma switches."""
     controller = hass.data[TAHOMA_DOMAIN]['controller']
     devices = []
     for switch in hass.data[TAHOMA_DOMAIN]['devices']['switch']:
diff --git a/tests/components/homekit/test_type_security_systems.py b/tests/components/homekit/test_type_security_systems.py
index da5dac2d81b..577d2f2175d 100644
--- a/tests/components/homekit/test_type_security_systems.py
+++ b/tests/components/homekit/test_type_security_systems.py
@@ -96,7 +96,7 @@ async def test_switch_set_state(hass):
 
 @pytest.mark.parametrize('config', [{}, {ATTR_CODE: None}])
 async def test_no_alarm_code(hass, config):
-    """Test accessory if security_system doesn't require a alarm_code."""
+    """Test accessory if security_system doesn't require an alarm_code."""
     entity_id = 'alarm_control_panel.test'
 
     hass.states.async_set(entity_id, None)
diff --git a/tests/components/media_player/test_blackbird.py b/tests/components/media_player/test_blackbird.py
index eea6295b79e..7c85775949c 100644
--- a/tests/components/media_player/test_blackbird.py
+++ b/tests/components/media_player/test_blackbird.py
@@ -14,7 +14,7 @@ from homeassistant.components.media_player.blackbird import (
 
 
 class AttrDict(dict):
-    """Helper clas for mocking attributes."""
+    """Helper class for mocking attributes."""
 
     def __setattr__(self, name, value):
         """Set attribute."""
diff --git a/tests/components/sensor/test_sigfox.py b/tests/components/sensor/test_sigfox.py
index dcdeef56b98..569fab584ad 100644
--- a/tests/components/sensor/test_sigfox.py
+++ b/tests/components/sensor/test_sigfox.py
@@ -38,7 +38,7 @@ class TestSigfoxSensor(unittest.TestCase):
         self.hass.stop()
 
     def test_invalid_credentials(self):
-        """Test for a invalid credentials."""
+        """Test for invalid credentials."""
         with requests_mock.Mocker() as mock_req:
             url = re.compile(API_URL + 'devicetypes')
             mock_req.get(url, text='{}', status_code=401)
@@ -47,7 +47,7 @@ class TestSigfoxSensor(unittest.TestCase):
         assert len(self.hass.states.entity_ids()) == 0
 
     def test_valid_credentials(self):
-        """Test for a valid credentials."""
+        """Test for valid credentials."""
         with requests_mock.Mocker() as mock_req:
             url1 = re.compile(API_URL + 'devicetypes')
             mock_req.get(url1, text='{"data":[{"id":"fake_type"}]}',
diff --git a/tests/components/test_folder_watcher.py b/tests/components/test_folder_watcher.py
index 16ec7a58a02..b5ac9cca9d9 100644
--- a/tests/components/test_folder_watcher.py
+++ b/tests/components/test_folder_watcher.py
@@ -8,7 +8,7 @@ from tests.common import MockDependency
 
 
 async def test_invalid_path_setup(hass):
-    """Test that a invalid path is not setup."""
+    """Test that an invalid path is not setup."""
     assert not await async_setup_component(
         hass, folder_watcher.DOMAIN, {
             folder_watcher.DOMAIN: {
diff --git a/tests/components/test_prometheus.py b/tests/components/test_prometheus.py
index 6cc0e4fcada..e336a28eb03 100644
--- a/tests/components/test_prometheus.py
+++ b/tests/components/test_prometheus.py
@@ -8,7 +8,7 @@ import homeassistant.components.prometheus as prometheus
 
 @pytest.fixture
 def prometheus_client(loop, hass, aiohttp_client):
-    """Initialize a aiohttp_client with Prometheus component."""
+    """Initialize an aiohttp_client with Prometheus component."""
     assert loop.run_until_complete(async_setup_component(
         hass,
         prometheus.DOMAIN,
diff --git a/tests/test_core.py b/tests/test_core.py
index 1fcd9416f36..4abce180093 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -375,7 +375,7 @@ class TestEventBus(unittest.TestCase):
         self.assertEqual(1, len(runs))
 
     def test_thread_event_listener(self):
-        """Test a  event listener listeners."""
+        """Test thread event listener."""
         thread_calls = []
 
         def thread_listener(event):
@@ -387,7 +387,7 @@ class TestEventBus(unittest.TestCase):
         assert len(thread_calls) == 1
 
     def test_callback_event_listener(self):
-        """Test a  event listener listeners."""
+        """Test callback event listener."""
         callback_calls = []
 
         @ha.callback
@@ -400,7 +400,7 @@ class TestEventBus(unittest.TestCase):
         assert len(callback_calls) == 1
 
     def test_coroutine_event_listener(self):
-        """Test a  event listener listeners."""
+        """Test coroutine event listener."""
         coroutine_calls = []
 
         @asyncio.coroutine