Kinds of Sentence:
Sentences can be classified into five categories, according to their meaning or function.

অর্থ বা কাজের ওপর ভিত্তি করে ইংরেজিতে Sentence কে সাধারণত পাঁচ ভাগে ভাগ করা যায়।

They are:-

1. Assertive Sentence.
2. Interrogative Sentence.
3. Imperative Sentence.
4. Optative Sentence.
5. Exclamatory Sentence.

Assertive Sentence:

An assertive sentence is a simple/general statement or assertion, either affirmative or negative.

কোনো সাধারণ বিবৃতি বা বক্তব্যকে Assertive Sentence (বিবৃতিমূলক বাক্য) বলে

Pattern:
Subject + verb + object/complement/adverb/adjective
Example:
-English is an International Language. (Affirmative)
-We do not do bad things. (Negative)
-Everybody should know English. (Modal auxiliaries)

Interrogative Sentence:

An interrogative sentence asks question about a person or thing(s). It always ends with a note of interrogation a.k.a. question mark (?).

There are two ways to form an interrogative sentence.

I. Beginning with helping verbs (am, is, are, was, were, have, has, had) or modal auxiliaries (shall, should, will, would, can, could, may, might, etc.).
Example:
- Do you have your assignment ready?
- Does he speak English?
- Did she work abroad?
- Should I go there?
- Can you hear the sound?
- Don’t you want any food? (Negative)

II. Beginning with some specific words like who, which, what, when, where, why, how, whom, how much, how many, etc. [These are known as ‘WH’ questions.]
Example:
- How is your business going on?
- Who fixed the computer?
- Whom do you support?
- What are you expecting from me?
- What time is it now?
- How many people have died there?

Imperative Sentence:

A sentence that expresses a request, command, order, advice, suggestion, etc. is an imperative sentence.
In an imperative sentence, the subject is usually unexpressed; it is understood rather.

Pattern:
Subject (Invisible) + verb + object / where
Example:
- Take care of you.
- Give me the pen.
- Do it now.
- Be honest.
- Come here
- Never tell a lie
- Do not laugh at other's helplessness.
- Let him go there.

Optative Sentence:

Wish, desire, prayer, etc. are expressed by the Optative sentence.

Pattern:
May + Assertive
Example:
- May you live long.
- May Allah bless you.
- Wish you all the best.
- Long live Bangladesh. (Can be formed without ‘may’)

Exclamatory Sentence:

Exclamatory is a sentence which expresses strong/sudden feeling or emotion like surprise, pain, delight, anger, disgust, etc.

Pattern:
Alas/ Hurrah/ Bravo/ What/ How etc. + Others
Example:
- Hurrah! Our cricket team has won the series.
- Alas! He has failed the competition.
- Bravo! You have done a great job.
- What a talented girl she is!
- How sweetly the cuckoo sings!
- What a wonderful land Bangladesh is!
- Were I a Super Hero!
- What a pity!
- Fantastic!
- What an idea!
- Put that down now!
- Leave the package at the door.
- Walk softly, please.

Structure of a Sentence:
According to structure, sentences are of three types.
I. Simple Sentence.
II. Complex Sentence.
III. Compound Sentence.

I. Simple Sentence:

Simple sentence is structured with only one subject and one finite verb.
Simple sentence has only one independent clause.

Pattern:
Subject + finite verb + complement
Exmaple: - Bangladesh is a populated country
- Life is not a bed of roses
- Human is the superior in this planet.

II. Complex Sentence:

A sentence consisting of one principal clause and one or more sub-ordinate clause(s) is a complex sentence.

Example:
- If you work hard, you will shine in life. (Here, ‘if you work hard’ is sub-ordinate clause and ‘you will shine in life’ is main or principal clause.)

Sub-ordinate clause begins with conjunctions like who, which, that, when, how, where, while, if, whether, because, since, as, though, although, till, until, unless, before, after, so that, whenever, wherever, whoever, whatever, etc.

Example: - I know where he lives.
- I do not know what his name is.
- While there is life there is hope.
- We eat so that we can survive.

III. Compound Sentence:

A sentence having more than one principal clauses, linked by one or more coordinating conjunctions, preceded by a comma, is called compound sentence.

Conjunctions that are used in compound sentences are and, but, or, for, nor, also, however, moreover, thus, so, therefore, else, still, as well as, accordingly, otherwise, yet, not yet, but also, either or, neither nor, on the contrary, etc.

Example:
- Respect others, and others will respect you.
- He loves us, but he does not show it.