Introduction to Conjunctions

Have you ever noticed how short, choppy sentences can make your writing feel a bit like a robot talking? For example: I went to the park. It was raining. I had fun.

To make our writing flow beautifully, we use "glue words." In English, these are called conjunctions. A conjunction is a word used to link words, phrases, or clauses together. By the end of this page, you will know how to use the two main types: co-ordinating and subordinating conjunctions.

Quick Note: To understand conjunctions, it helps to know what a clause is. A clause is a group of words that contains a verb. Some clauses make sense on their own (Main Clauses), and some need a bit of help. (For more on this, see Chapter G3: Clauses: main, subordinate and relative).

Co-ordinating Conjunctions

Co-ordinating conjunctions are used to join two parts of a sentence that are equally important. Usually, they join two main clauses together to create a compound sentence.

In your KS2 studies, the three most important co-ordinating conjunctions to remember are:

  • And (used to add more information)
  • But (used to show a change or a contrast)
  • Or (used to show a choice)

How to use them:

Imagine you have two "Main Clauses" (sentences that make sense by themselves):

Clause 1: I like football.
Clause 2: I like tennis.

We can glue them together: I like football and I like tennis.

Other examples:
I wanted to go outside, but it was too cold. (Contrast)
Do you want tea or would you prefer juice? (Choice)

Key Takeaway:

Co-ordinating conjunctions (and, but, or) join equal parts of a sentence. Think of them as a bridge between two identical islands.

Subordinating Conjunctions

Subordinating conjunctions are a little different. They join a main clause to a subordinate clause. A subordinate clause is a "helper" clause—it adds extra information (like when, why, or if something happened) but doesn't make sense all by itself.

The most common subordinating conjunctions you need to know are:

  • When (tells us the time)
  • If (tells us a condition)
  • That (links ideas)
  • Because (gives a reason or cause)
  • Although (shows a surprise or contrast)

How to use them:

Look at this sentence: I wore my coat because it was freezing.

"I wore my coat" is the main clause (it makes sense alone).
"because it was freezing" is the subordinate clause. It tells us why I wore the coat. Without the first part, "because it was freezing" feels unfinished!

More examples:
I will go to the party if I finish my homework.
The teacher said that we did a great job.
We went for a walk although it was getting dark.

Key Takeaway:

Subordinating conjunctions (when, if, that, because, although) introduce extra information. They turn a simple sentence into a more detailed one!

Where does the Conjunction go?

Don't worry if you see a conjunction at the start of a sentence. While co-ordinating conjunctions (and, but, or) usually sit in the middle, subordinating conjunctions can move around!

Option A: I ate my dinner when I got home.
Option B: When I got home, I ate my dinner.

Both of these are correct! Just remember: if you start a sentence with a subordinating conjunction, you usually need a comma after the first clause.

Common Mistakes to Avoid

1. Using too many "ands": Try not to use "and" over and over again in the same sentence. It can make the reader feel breathless!
Mistake: I went home and I saw my dog and we played and then I had a snack.

2. Forgetting the "glue": Sometimes students write two sentences next to each other without any conjunction or punctuation. This is called a "run-on sentence."
Mistake: I was tired I went to bed.
Fix: I was tired so I went to bed. (Note: while 'so' is common, remember to focus on the core list like and, but, or, because for your tests!)

Quick Review Quiz

Try to identify the conjunction in these sentences and decide if it is co-ordinating or subordinating:

  1. I bought a burger and I ate it quickly.
  2. We stayed inside because the wind was too strong.
  3. You can have the red apple or the green one.
  4. If you are helpful, you might get a reward.

Answers:
1. And (Co-ordinating)
2. Because (Subordinating)
3. Or (Co-ordinating)
4. If (Subordinating)

Final Summary Checklist:
  • Conjunctions are words that join parts of sentences.
  • Co-ordinating conjunctions are and, but, or.
  • Subordinating conjunctions include when, if, that, because, although.
  • Conjunctions help express time (when), place, and cause (because).