Subordinating Conjunctions (KS2) Explained

If your child has come home talking about subordinating conjunctions, you are in the right place. It sounds like a mouthful, but the idea is simple, and once it clicks it helps children write longer, clearer sentences. This guide explains what a subordinating conjunction is, shares a friendly Year 6 list, and walks through how it all fits together with plenty of examples.

What is a subordinating conjunction?

A subordinating conjunction is a joining word that adds extra information to a sentence by starting a part called a subordinate clause. That extra part cannot stand on its own. It leans on the main part of the sentence to make complete sense.

Here is a simple example, with the subordinating conjunction in bold:

We went inside because it started to rain.

The words "it started to rain" tell us why we went inside. On their own, beginning with because, they feel unfinished. They need the main idea, "We went inside", to lean on. That joining word because is the subordinating conjunction.

Subordinating conjunctions list for KS2

There are quite a few, and children do not need to memorise every one. It helps far more to recognise the common ones and use them confidently. Here are the subordinating conjunctions most useful at KS2, grouped by the job they tend to do.

A few words can do more than one job. The word as appears twice above because it can show both a reason and a time, and since works the same way ("since you asked" shows a reason, "since Monday" shows time). Do not worry if a word turns up in more than one group. The important thing is that each one introduces a subordinate clause.

How they introduce a subordinate clause

The job of a subordinating conjunction is to open a subordinate clause and hook it onto the main clause. Look at how the bold word starts the extra information each time:

• I always read before I go to sleep.
• She kept practising until she could spell every word.
• We can play outside if the weather stays dry.
• He smiled although he had not won.

In each sentence, the part beginning with the bold word is the subordinate clause. Try reading just that part out loud, for example "until she could spell every word". It sounds like it is waiting for something, and that is the clue that it is subordinate.

Main clause vs subordinate clause: how the two fit together

This is the heart of it, and it is worth slowing down on. Every sentence like the ones above has two parts working together.

• A main clause makes complete sense on its own. "We can play outside" is a perfectly good sentence by itself.
• A subordinate clause does not make complete sense on its own. "if the weather stays dry" leaves you waiting for more.

Put them together and you get a longer, richer sentence:

We can play outside if the weather stays dry.

The main clause is in bold and the subordinate clause is in italics. The lovely thing is that you can usually flip them around. The subordinate clause can come first instead:

If the weather stays dry, we can play outside.

The meaning is the same. Only the order, and one comma, has changed. More on that comma shortly. If you would like to go deeper into how clauses work, our guide to relative clauses explains another type your child will meet in Year 6.

Subordinating vs coordinating conjunctions: the key difference

Children often mix these two up, so this is a great thing to talk about at home. Both are joining words, but they join in very different ways.

A coordinating conjunction joins two parts of equal importance. The handy way to remember them is the word FANBOYS: for, and, nor, but, or, yet, so. Each side could often stand alone:

I tidied my room and I read my book.

Here, "I tidied my room" and "I read my book" are both complete on their own. They are equal partners.

A subordinating conjunction is different. It makes one part depend on the other:

I read my book after I tidied my room.

Now "after I tidied my room" cannot stand alone. It has become subordinate. That is the key difference: coordinating conjunctions join equals, while subordinating conjunctions make one clause lean on another. You can read more in our companion guides on coordinating conjunctions and FANBOYS and using commas at KS2.

Commas with subordinate clauses at the start of a sentence

Here is a neat rule that can come up in the Year 6 test, and it is genuinely useful for clear writing.

When the subordinate clause comes first, put a comma after it:

Although it was late, we finished the puzzle.

Because she practised every day, her spelling improved.

When the main clause comes first, you usually do not need a comma:

We finished the puzzle although it was late.

Her spelling improved because she practised every day.

A simple way to remember it: if the sentence starts with the joining word, it will probably need a comma in the middle. If the joining word sits in the middle, you can usually leave the comma out.

How this shows up in the Year 6 SPaG test

In the Key Stage 2 grammar, punctuation and spelling test, children are often asked to do one of a few things with subordinating conjunctions. They might need to:

• choose the best word to complete a sentence, for example picking because, although or until
• name or identify the subordinate clause in a sentence
• add a missing comma when a subordinate clause comes first
• write their own sentence using a given subordinating conjunction

A calm, friendly way to practise at home is to play with a few favourite joining words. Start with a plain main clause, such as "We made pancakes", then take turns adding a subordinate clause with because, before, when or although. You will quickly hear which sentences sound complete and which are still waiting for more. For the bigger picture of what the test covers, see our overview of the SPaG test.

How SATS LION helps

SATS LION turns this kind of grammar practice into a short, friendly daily quest, so subordinating conjunctions become something to play with rather than worry about. Questions are written to match the KS2 curriculum and checked by a person before they reach your child, and the calm, game-first approach is designed to build confidence at a comfortable pace. If you would like to see how it works, you can explore the features here.