diff --git a/aiogram/contrib/fsm_storage/memory.py b/aiogram/contrib/fsm_storage/memory.py
index ac463d14..f8670ec4 100644
--- a/aiogram/contrib/fsm_storage/memory.py
+++ b/aiogram/contrib/fsm_storage/memory.py
@@ -86,19 +86,24 @@ class MemoryStorage(BaseStorage):
     def has_bucket(self):
         return True
 
-    async def get_bucket(self, *, chat: typing.Union[str, int, None] = None, user: typing.Union[str, int, None] = None,
+    async def get_bucket(self, *,
+                         chat: typing.Union[str, int, None] = None,
+                         user: typing.Union[str, int, None] = None,
                          default: typing.Optional[dict] = None) -> typing.Dict:
         chat, user = self.check_address(chat=chat, user=user)
         user = self._get_user(chat, user)
         return user['bucket']
 
-    async def set_bucket(self, *, chat: typing.Union[str, int, None] = None, user: typing.Union[str, int, None] = None,
+    async def set_bucket(self, *,
+                         chat: typing.Union[str, int, None] = None,
+                         user: typing.Union[str, int, None] = None,
                          bucket: typing.Dict = None):
         chat, user = self.check_address(chat=chat, user=user)
         user = self._get_user(chat, user)
         user['bucket'] = bucket
 
-    async def update_bucket(self, *, chat: typing.Union[str, int, None] = None,
+    async def update_bucket(self, *,
+                            chat: typing.Union[str, int, None] = None,
                             user: typing.Union[str, int, None] = None,
                             bucket: typing.Dict = None, **kwargs):
         chat, user = self.check_address(chat=chat, user=user)
diff --git a/aiogram/dispatcher/handler.py b/aiogram/dispatcher/handler.py
index 8972958c..139c6011 100644
--- a/aiogram/dispatcher/handler.py
+++ b/aiogram/dispatcher/handler.py
@@ -72,7 +72,7 @@ class Handler:
                         context.set_value('handler', handler)
                         await self.dispatcher.middleware.trigger(f"process_{self.middleware_key}", args)
                     response = await handler(*args)
-                    if results is not None:
+                    if response is not None:
                         results.append(response)
                     if self.once:
                         break
diff --git a/aiogram/dispatcher/storage.py b/aiogram/dispatcher/storage.py
index e50b8de7..b7e733d7 100644
--- a/aiogram/dispatcher/storage.py
+++ b/aiogram/dispatcher/storage.py
@@ -12,13 +12,14 @@ THROTTLE_MANAGER = '$throttle_manager'
 
 class BaseStorage:
     """
-    In states-storage you can save current user state and data for all steps
+    You are able to save current user's state
+    and data for all steps in states-storage
     """
 
     async def close(self):
         """
-        Need override this method and use when application is shutdowns.
-        You can save data or etc.
+        You have to override this method and use when application shutdowns.
+        Perhaps you would like to save data and etc.
 
         :return:
         """
@@ -26,7 +27,7 @@ class BaseStorage:
 
     async def wait_closed(self):
         """
-        You need override this method for all asynchronously storage's like Redis.
+        You have to override this method for all asynchronous storages (e.g., Redis).
 
         :return:
         """
@@ -37,34 +38,33 @@ class BaseStorage:
                       chat: typing.Union[str, int, None] = None,
                       user: typing.Union[str, int, None] = None) -> (typing.Union[str, int], typing.Union[str, int]):
         """
-        In all methods of storage chat or user is always required.
-        If one of this is not presented, need set the missing value based on the presented.
+        In all storage's methods chat or user is always required.
+        If one of them is not provided, you have to set missing value based on the provided one.
 
-        This method performs the above action.
+        This method performs the check described above.
 
         :param chat:
         :param user:
         :return:
         """
-        if chat is not None and user is not None:
-            return chat, user
-        elif user is None and chat is not None:
+        if chat is None and user is None:
+            raise ValueError('`user` or `chat` parameter is required but no one is provided!')
+
+        if user is None and chat is not None:
             user = chat
-            return chat, user
         elif user is not None and chat is None:
             chat = user
-            return chat, user
-        raise ValueError('User or chat parameters is required but anyone is not presented!')
+        return chat, user
 
     async def get_state(self, *,
                         chat: typing.Union[str, int, None] = None,
                         user: typing.Union[str, int, None] = None,
                         default: typing.Optional[str] = None) -> typing.Optional[str]:
         """
-        Get current state of user in chat. Return value stored in `default` parameter if record is not found.
+        Get current state of user in chat. Return `default` if no record is found.
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
@@ -78,10 +78,10 @@ class BaseStorage:
                        user: typing.Union[str, int, None] = None,
                        default: typing.Optional[typing.Dict] = None) -> typing.Dict:
         """
-        Get state-data for user in chat. Return `default` if data is not presented in storage.
+        Get state-data for user in chat. Return `default` if no data is provided in storage.
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
@@ -95,10 +95,10 @@ class BaseStorage:
                         user: typing.Union[str, int, None] = None,
                         state: typing.Optional[typing.AnyStr] = None):
         """
-        Setup new state for user in chat
+        Set new state for user in chat
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
@@ -113,8 +113,8 @@ class BaseStorage:
         """
         Set data for user in chat
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
@@ -132,8 +132,8 @@ class BaseStorage:
 
         You can use data parameter or|and kwargs.
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param data:
         :param chat:
@@ -147,10 +147,10 @@ class BaseStorage:
                          chat: typing.Union[str, int, None] = None,
                          user: typing.Union[str, int, None] = None):
         """
-        Reset data dor user in chat.
+        Reset data for user in chat.
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
@@ -163,10 +163,11 @@ class BaseStorage:
                           user: typing.Union[str, int, None] = None,
                           with_data: typing.Optional[bool] = True):
         """
-        Reset state for user in chat. You can use this method for finish conversations.
+        Reset state for user in chat.
+        You may desire to use this method when finishing conversations.
 
         Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
@@ -184,8 +185,8 @@ class BaseStorage:
         """
         Finish conversation for user in chat.
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
@@ -201,10 +202,10 @@ class BaseStorage:
                          user: typing.Union[str, int, None] = None,
                          default: typing.Optional[dict] = None) -> typing.Dict:
         """
-        Get state-data for user in chat. Return `default` if data is not presented in storage.
+        Get bucket for user in chat. Return `default` if no data is provided in storage.
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
@@ -218,10 +219,10 @@ class BaseStorage:
                          user: typing.Union[str, int, None] = None,
                          bucket: typing.Dict = None):
         """
-        Set data for user in chat
+        Set bucket for user in chat
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
@@ -235,12 +236,12 @@ class BaseStorage:
                             bucket: typing.Dict = None,
                             **kwargs):
         """
-        Update data for user in chat
+        Update bucket for user in chat
 
-        You can use data parameter or|and kwargs.
+        You can use bucket parameter or|and kwargs.
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param bucket:
         :param chat:
@@ -254,10 +255,10 @@ class BaseStorage:
                            chat: typing.Union[str, int, None] = None,
                            user: typing.Union[str, int, None] = None):
         """
-        Reset data dor user in chat.
+        Reset bucket dor user in chat.
 
-        Chat or user is always required. If one of this is not presented,
-        need set the missing value based on the presented
+        Chat or user is always required. If one of them is not provided,
+        you have to set missing value based on the provided one.
 
         :param chat:
         :param user:
diff --git a/aiogram/types/inline_keyboard.py b/aiogram/types/inline_keyboard.py
index 7c859e6e..1b5c8011 100644
--- a/aiogram/types/inline_keyboard.py
+++ b/aiogram/types/inline_keyboard.py
@@ -34,7 +34,8 @@ class InlineKeyboardMarkup(base.TelegramObject):
         Add buttons
 
         :param args:
-        :return:
+        :return: self
+        :rtype: :obj:`types.InlineKeyboardMarkup`
         """
         row = []
         for index, button in enumerate(args, start=1):
@@ -44,13 +45,15 @@ class InlineKeyboardMarkup(base.TelegramObject):
                 row = []
         if len(row) > 0:
             self.inline_keyboard.append(row)
+        return self
 
     def row(self, *args):
         """
         Add row
 
         :param args:
-        :return:
+        :return: self
+        :rtype: :obj:`types.InlineKeyboardMarkup`
         """
         btn_array = []
         for button in args:
@@ -63,11 +66,14 @@ class InlineKeyboardMarkup(base.TelegramObject):
         Insert button to last row
 
         :param button:
+        :return: self
+        :rtype: :obj:`types.InlineKeyboardMarkup`
         """
         if self.inline_keyboard and len(self.inline_keyboard[-1] < self.row_width):
             self.inline_keyboard[-1].append(button)
         else:
             self.add(button)
+        return self
 
 
 class InlineKeyboardButton(base.TelegramObject):
diff --git a/aiogram/types/reply_keyboard.py b/aiogram/types/reply_keyboard.py
index 197202c2..e09ae4c4 100644
--- a/aiogram/types/reply_keyboard.py
+++ b/aiogram/types/reply_keyboard.py
@@ -37,7 +37,8 @@ class ReplyKeyboardMarkup(base.TelegramObject):
         Add buttons
 
         :param args:
-        :return:
+        :return: self
+        :rtype: :obj:`types.ReplyKeyboardMarkup`
         """
         row = []
         for index, button in enumerate(args):
@@ -47,13 +48,15 @@ class ReplyKeyboardMarkup(base.TelegramObject):
                 row = []
         if len(row) > 0:
             self.keyboard.append(row)
+        return self
 
     def row(self, *args):
         """
         Add row
 
         :param args:
-        :return:
+        :return: self
+        :rtype: :obj:`types.ReplyKeyboardMarkup`
         """
         btn_array = []
         for button in args:
@@ -66,11 +69,14 @@ class ReplyKeyboardMarkup(base.TelegramObject):
         Insert button to last row
 
         :param button:
+        :return: self
+        :rtype: :obj:`types.ReplyKeyboardMarkup`
         """
         if self.keyboard and len(self.keyboard[-1]) < self.row_width:
             self.keyboard[-1].append(button)
         else:
             self.add(button)
+        return self
 
 
 class KeyboardButton(base.TelegramObject):
@@ -84,8 +90,11 @@ class KeyboardButton(base.TelegramObject):
     request_contact: base.Boolean = fields.Field()
     request_location: base.Boolean = fields.Field()
 
-    def __init__(self, text: base.String, request_contact: base.Boolean = None, request_location: base.Boolean = None):
-        super(KeyboardButton, self).__init__(text=text, request_contact=request_contact,
+    def __init__(self, text: base.String,
+                 request_contact: base.Boolean = None,
+                 request_location: base.Boolean = None):
+        super(KeyboardButton, self).__init__(text=text,
+                                             request_contact=request_contact,
                                              request_location=request_location)
 
 
diff --git a/aiogram/types/user.py b/aiogram/types/user.py
index 40e1f7bc..d27f2f87 100644
--- a/aiogram/types/user.py
+++ b/aiogram/types/user.py
@@ -36,7 +36,8 @@ class User(base.TelegramObject):
     @property
     def mention(self):
         """
-        You can get mention to user (If user have username, otherwise return full name)
+        You can get user's username to mention him
+        Full name will be returned if user has no username
 
         :return: str
         """
@@ -47,7 +48,7 @@ class User(base.TelegramObject):
     @property
     def locale(self) -> 'babel.core.Locale' or None:
         """
-        This property require `Babel <https://pypi.python.org/pypi/Babel>`_ module
+        This property requires `Babel <https://pypi.python.org/pypi/Babel>`_ module
 
         :return: :class:`babel.core.Locale`
         :raise: ImportError: when babel is not installed.