An auxiliary verb or helping verb is a verb that is used to determine the tense, mood, or voice of another verb and helps to complete the meaning of main verb.

An article is a word that helps us to customize a noun which is a person, place, idea or object. (A, an এবং the শব্দগুলোকে Article বলা হয়।)

Sentences which states a simple statement are known as assertive, declarative or statement sentence. যে sentence দ্বারা কোন বিবৃতি প্রদান করা হয় তাকে assertive sentence বলে।

Sentences which states or ask any questions are known as interrogative sentence. যে sentence দ্বারা কোন প্রশ্ন করা হয় তাকে Interrogative Sentence বলে।

A sentence which expresses requests, advice, orders, commands, proposals, or suggestions are known as imperative sentence.

Optative sentence is a grammatical category of mood which expresses wish, prayer, hope, desire, curse or etc.