Nの代わりに
Vる/た /vない + かわりに
Another person will do something, another object will be used, or another action will be taken
V た + まま
N +のまま
Use when you say that a situation is unchanged. You can also use when the current situation is not being done even though it must be.
日本語が難しくなったままです
入れ (ます form of a verb) instead of て form
Like the て form in terms of order of doing things. Use the ます form in place of て ie
テレビをみ、ご飯くを食べる
V stem + きる
きる is used to say that something is all done or done to completeness. きれない means not complete as the task is too much.