Relative Clauses and Relative Pronouns (KS2)

Relative clauses are one of the grammar skills Year 6 pupils meet in the run-up to the KS2 SATs, and they sound far trickier than they really are. In plain terms, a relative clause is just a way of adding extra detail about a person, place or thing inside a sentence. Once your child can spot the little words that start them, the rest tends to click into place.

What is a relative clause?

A relative clause is a type of subordinate clause that gives us more information about a noun (a person, place or thing). It nearly always begins with a relative pronoun such as who, which or that, and it cannot stand on its own as a full sentence.

Here is a simple example:

• The girl who won the race was delighted.

The main idea is "The girl was delighted." The relative clause who won the race tells us which girl we mean and adds detail about her. On its own, "who won the race" does not make sense, which is exactly why it is a clause that depends on the rest of the sentence.

Relative pronouns: who, whom, whose, which and that

Relative clauses are introduced by relative pronouns. Knowing who, which, that and a couple of others is the key to the whole topic. Here is when to use each one.

Two extra words, where and when, can act in a similar way when they point back to a place or a time, as in "the day when we met" or "the park where we play".

A handy tip for pupils: use who for people and which for things. That can often replace either when the detail is essential to the meaning.

Relative clauses that add extra information

Relative clauses are brilliant for turning a plain sentence into a detailed one. Instead of writing two short sentences, your child can fold one idea neatly inside the other.

• Plain: The castle was huge. It stood on a hill.
• Improved: The castle, which stood on a hill, was huge.

This is closely linked to building expanded noun phrases: both add description around a noun. The difference is that a relative clause contains its own verb (here, stood), so it is a clause rather than just a phrase.

Embedded relative clauses and the comma rule

An embedded relative clause is one that drops into the middle of a sentence, interrupting the main idea to describe a noun. When a relative clause adds extra, non-essential information like this, we mark it off with a pair of commas, one before and one after.

• My brother, who is ten, loves football.
• The old oak tree, which we planted years ago, is enormous.

You can test whether commas are needed by removing the clause. If the sentence still makes complete sense, the information is extra and the commas belong, as in "My brother loves football." Brackets or dashes can do the same job, but commas are the most common choice and the safest for the SATs. If you would like more on this, our guide to using commas in KS2 goes further.

There is one important exception. When the relative clause is essential to identify which noun you mean, you do not use commas:

• The pupil who finished first won a prize.

Here, "who finished first" tells us exactly which pupil, so it is essential and stays comma-free.

Relative clauses vs other subordinate clauses

A relative clause is a kind of subordinate clause, so it depends on a main clause to make sense. The difference lies in how it connects.

• A relative clause joins on using a relative pronoun (who, which, that) and describes a noun: "The shop that sells comics is shut."
• Other subordinate clauses join on using a subordinating conjunction such as because, although or when, and they usually tell us about the whole action: "We went home because it was raining."

So the quick check is the joining word. A relative pronoun signals a relative clause; a subordinating conjunction signals a different type of subordinate clause.

How relative clauses are tested in the KS2 SPaG paper

In the KS2 grammar, punctuation and spelling test, relative clauses can come up in a few familiar ways. Pupils might be asked to:

• underline or tick the relative clause in a sentence,
• choose the correct relative pronoun to complete a sentence,
• add a relative clause of their own to give more detail, or
• insert the missing commas around an embedded relative clause.

For a fuller picture of the paper and how marks are awarded, see our overview of what the SPaG test involves. Knowing the names of the relative pronouns and the comma rule covers most of what the paper expects.

Practice: add a relative clause

A lovely way to practise is to take a plain sentence and make it more detailed by slotting in a relative clause. Try these together, saying the new sentence aloud first:

1. The dog barked. (Add who/which detail: The dog, which had muddy paws, barked.)
2. My friend lives nearby. (My friend, who is in my class, lives nearby.)
3. We visited the museum. (We visited the museum that opened last year.)

Notice how sentences 1 and 2 use commas because the detail is extra, while sentence 3 has no commas because "that opened last year" tells us which museum. Practising the difference is exactly what builds confidence.

How SATS LION helps

SATS LION turns relative clauses and the rest of KS2 SPaG into short, friendly challenges inside Word Mage Academy, so your child practises spotting relative pronouns and placing commas without it feeling like a worksheet. Every question is matched to the England National Curriculum and revisits tricky ideas at a gentle pace.

Curious to see it in action? Take a look at what is inside SATS LION.