Clauses and conjunctions: a guide for Year 6
Clauses are the building blocks of every sentence, and conjunctions are what join them. Once children can find the verb and ask whether a clause makes sense on its own, most clause questions in the SATs become straightforward.
What is a clause?
A clause is a group of words that contains a verb, and usually a subject. The bell rang is a clause. After lunch is not: it has no verb, so it is a phrase. That one distinction, verb or no verb, is the most useful test children can learn, because questions in the SATs regularly ask whether a group of words is a clause or a phrase.
Main clauses and subordinate clauses
A main clause makes sense on its own as a complete sentence. A subordinate clause adds information but does not make sense on its own; it depends on a main clause. In the strips below, the subordinate clause is marked.
- The bell rang when the lesson ended.
- Although it was late, we kept reading.
- She smiled because she had finished first.
Read the marked parts on their own and they feel unfinished: Although it was late… what? That incomplete feeling is the test. Subordinate clauses usually begin with a subordinating conjunction (because, although, when) or a relative pronoun (who, which, that).
When a subordinate clause comes first, it is followed by a comma, just like a fronted adverbial. When it comes second, it usually isn't.
Co-ordinating conjunctions
Co-ordinating conjunctions join two things of equal importance, and when they join two main clauses they make a compound sentence. The main ones are and, but, or and so (with for, nor and yet, which some schools teach with the mnemonic FANBOYS).
- It was raining, so we stayed in.Both halves would work as sentences on their own.
A quick test: remove the conjunction, and if both parts still stand as sentences, it is co-ordinating. Children also need to use these well in their own writing, which mostly means choosing the conjunction that shows the real relationship (but for contrast, so for result) instead of linking everything with and.
Subordinating conjunctions
A subordinating conjunction introduces a subordinate clause and shows how it relates to the main clause.
| Relationship | Conjunctions | Example |
|---|---|---|
| Time | when, while, before, after, until, since, as soon as | We waited until the rain stopped. |
| Reason | because, as, since | He laughed because the joke was terrible. |
| Contrast | although, though, whereas, even though | Although it was cold, we swam. |
| Condition | if, unless | We'll go out unless it snows. |
The subordinate clause can come before or after the main clause, which gives children an easy way to vary their sentences.
Preposition or conjunction?
Words like after, before, since and until can be either. The SATs test this distinction directly, and the rule is the same as for phrases and clauses: look at what follows.
- We waited until lunchtime.Preposition: a noun follows.
- We waited until the bus arrived.Conjunction: a clause with a verb follows.
How clauses and conjunctions are tested in the SATs
- Underline the subordinate clause or the main clause in a sentence.
- Tick the sentence that contains a subordinate clause, or the one that is a complex sentence.
- Circle the conjunction, or choose a suitable conjunction to complete a sentence.
- Clause or phrase? Children decide whether a group of words is a clause or a phrase.
- Combine two sentences using a given conjunction, with correct punctuation.
When underlining, the whole clause counts. Children often stop after the conjunction or underline only part of the clause, which loses the mark.
Common mistakes
- Because I was tired.A subordinate clause on its own is not a sentence.
- Although it was late we kept reading.The clause ends at late; the comma goes there.
- Leaving subordinate clauses stranded as sentences (Because I was tired.), a common habit in children's writing.
- Confusing clauses and phrases. Finding the verb settles almost every case.
- Thinking the subordinate clause must come second. Show plenty of examples with it first.
- Calling however and therefore conjunctions. They link ideas but are adverbs, and they can't join two clauses with just a comma.
Teaching ideas
Does it stand alone?
Give pupils a set of clauses on cards, some main and some subordinate. They read each aloud and sort them into “complete” and “waiting for more”. Then they pair them up into complex sentences.
Swap the conjunction
Write I wanted to play outside ___ it was raining. Pupils try but, although, because and so in turn, and discuss which make sense and how the meaning changes. Choosing a conjunction is really about choosing a relationship between ideas.
Flip it
Children take a complex sentence, move the subordinate clause to the front and add the comma it now needs. Doing this in both directions makes the comma rule stick.
Upgrade a paragraph
Share a paragraph of short simple sentences and ask pupils to combine some of them using a range of conjunctions, keeping at least one short sentence for effect.
Try it: five quick questions
SATs-style questions to use as a starter or a quick check. Tap to see each answer.
Underline the subordinate clause: We stayed indoors because it was raining.
Show answer
because it was raining
Clause or phrase? after the match
Show answer
A phrase: there is no verb.
Circle the co-ordinating conjunction: I wanted to go, but the gate was locked.
Show answer
but
Add a comma: Although it was late we kept reading.
Show answer
Although it was late, we kept reading.
Is until a preposition or a conjunction in We waited until the bus arrived?
Show answer
A conjunction: it introduces a clause with a verb (arrived).
Free worksheets for this topic
Printable A4 PDFs with answers. Free to use in class or at home.
