Parts Of Speech

CONJUNCTION- is a joiner, a word that connects or joins words or sentences together.
Little conjuctions are called Coordinating Conjunctions.(It may help you remember these conjunctions by recalling that they all have fewer than four letters. Also, remember the acronym FANBOYS: For-And-Nor-But-Or-Yet-So). Be careful of the words 'then' and 'now'; neither is a coordinating conjunction, so what we say about coordinating conjunctions' roles in a sentence and punctuation does not apply to those two words.
Words join together by Conjunction:
cats AND dogs
Coffe Or tea
Poor BUT honest
big OR small
law AND order
Sentences join by Conjunction:
Take this AND give it to Ali.
Rama is rich BUT John is poor.
Ali works hard BECAUSE he wants to do well.
You can take it OR leave it.
IF he is there, I will talk to him.
I went home AFTER??I had finished work.
I don't know WHETHER he will come.
When to use comma:
When a coordinating conjunction connects two independent clauses, it is often (but not always) accompanied by a comma:
Ulysses wants to play for UConn, but he has had trouble meeting the academic requirements.
When the two independent clauses connected by a coordinating conjunction are nicely balanced or brief, many writers will omit the comma:
Ulysses has a great jump shot but he isn't quick on his feet.
The comma is always correct when used to separate two independent clauses connected by a coordinating conjunction. See Punctuation Between Two Independent Clauses for further help.
A comma is also correct when 'and' is used to attach the last item of a serial list, although many writers (especially in newspapers) will omit that final comma:
Ulysses spent his summer studying basic math, writing, and reading comprehension.
When a coordinating conjunction is used to connect all the elements in a series, a comma is not used:
Presbyterians and Methodists and Baptists are the prevalent Protestant congregations in Oklahoma.
A comma is also used with??'but' when expressing a contrast:
This is a useful rule, but difficult to remember.
In most of their other roles as joiners (other than joining independent clauses, that is), coordinating conjunctions can join two sentence elements without the help of a comma.
Hemingway and Fitzgerald are among the American expatriates of the between-the-wars era.
Hemingway was renowned for his clear style and his insights into American notions of male identity.
It is hard to say whether Hemingway or Fitzgerald is the more interesting cultural icon of his day.
Other conjunctions:
and/ after/as if/as/ although/before/but/ because/either..or/neither..nor/so...that/for/in order that/since/though/than/unless/until/when/whenever/whether/where/wherever/now that/