A conjunction is a word that connects words, phrases, or clauses.

e.g., but, and, because, although, since, unless, or, nor, yet, for, so, while, where, etc.

A conjunction can be a single-word conjunction (e.g., but, and, because, yet, since, unless, etc.) or a compound conjunction, which is a group of words (e.g., as long as, as far as, as well as, in order to, even if, so that, etc.).

Conjunctions are classified into three types:

  1. Coordinating Conjunction
  2. Subordinating Conjunction
  3. Correlative Conjunction

A coordinating conjunction connects words, phrases, or clauses of similar grammatical structure. Coordinating conjunctions are also known as coordinators.

Examples: but, and, or, so, nor, yet, for, etc.

They connect the following:

Word + Word
Phrase + Phrase
Clause + Clause

Read the following examples where the blue parts are words, phrases, or clauses joined together by coordinating conjunctions (e.g., but, and, or, because) shown in red color.

Examples.

• He closed the door and the window. (two words).
• She showed us her dog and cat. (two words)
• He broke his glass and cup. (two words).
• Would you like to have some tea or coffee? (two words).
• She is interested in reading stories and watching movies. (two phrases).
• You may meet me at my home or at my office. (two phrases).
• They usually play games in the street or in the garden. (two phrases).
• I waited for him, but he did not come. (two clauses).
• She requested him for help, but he did not help her. (two clauses).
• He always sings songs because he wants to become a singer.  (two clauses).

In each case, the elements joined by coordinating conjunctions have similar grammatical structure.

Before learning about subordinating conjunctions, it is essential to understand main clauses and subordinate clauses.

A clause is a group of words having a subject and a verb, e.g., he laughed. There are two types of clauses:

1. Main clause
2. Subordinate clause

Example:

• I saw a man who was laughing.

In this sentence, “I saw a man” is the main clause, which expresses a complete thought and can stand alone. “Who was laughing” is the subordinate clause, which cannot stand alone and depends on the main clause for its meaning. A subordinate clause is dependent on the main clause to make complete sense. Therefore, the subordinate clause is also known as a dependent clause. It is called a subordinate clause because it has a subordinate role in relation to the main clause in a sentence.

  A subordinating conjunction is a word that connects a subordinate clause to a main clause. In the example above, “who” functions as a subordinating conjunction. A subordinate clause generally comes after a main clause in a sentence. However, a sentence can also start with a subordinate clause followed by a main clause.

• Main clause + Subordinate clause
• Subordinate clause + Main clause

Regardless of placement, a subordinate clause always begins with a subordinating conjunction, which is considered part of the clause.

See the following examples where the blue part is the main clause and the red part is the subordinate clause. The underlined word is a subordinating conjunction.

Examples.

• We met the boy who had won the competition.
• I saw the man who had helped me last year.
• This is the car which I like the most.
• You can live a happy life provided that you think optimistically.
• We saw a car which was badly damaged in an accident.
• I will not tell him the secret even if he insists a lot.
• He gifted me a book which helped me in preparation for my exam.
• I will give you my camera whenever you need it.
• Although it is raining, it is too hot today.
• As far as I know, he is a nice person.
• If you avoid sugary foods, you can easily lose weight.
• Since most of the members are absent, we should cancel the meeting.

A correlative conjunction is a paired word. It joins words, phrases, or clauses having a reciprocal or complementary relationship.

Common correlative conjunctions include:

• Either … or
• Neither … nor
• Whether … or
• Both … and
• Not only … but also
• As … as
• Such … that
• Rather … than

Examples. 

• He will buy either a laptop or a camera.
• She likes neither tea nor coffee.
• Both pink and blue are my favorite colors.
• Both sugary juices and fatty foods cause weight gain.
• She is interested not only in watching movies but also in listening to music.
• You will find him either in the library or in the classroom.
• I would rather eat a burger than a pizza.
• It was such a cold day that we had to turn the heater on.
• He is as intelligent as you.