Subordinating conjunctions are one of those grammar terms that sounds far more complicated than it actually is. Children encounter them constantly in KS2 writing lessons and the GPS test — here's the plain-English version.
What a subordinating conjunction actually does
It joins two parts of a sentence where one part can't stand alone — it makes one part depend on the other. That dependent part is called a subordinate clause, which is why the joining word is called a subordinating conjunction.
"I stayed inside because it was raining." — "because it was raining" can't stand alone as a sentence; it depends on the first part.
The common KS2 list
because · although · since · unless · while · when · if · until · before · after · as · whereas
How this differs from a coordinating conjunction
Coordinating conjunctions (and, but, or) join two equal, independent ideas that could each stand alone. Subordinating conjunctions join an independent idea to a dependent one that couldn't stand alone by itself. This distinction is exactly what KS2 grammar tests check — not just "can you use the word," but "do you understand which type of joining it's doing."
A quick way to test understanding at home
Give your child two simple sentences and a subordinating conjunction, and ask them to join them: "I brushed my teeth. I went to bed." + "before" → "I brushed my teeth before I went to bed." This kind of quick verbal exercise, done a few times over a week, builds genuine fluency far better than memorising the list alone.
Why it matters beyond the test
Subordinating conjunctions are one of the simplest ways to make writing sound more sophisticated — turning two short, choppy sentences into one flowing one. It's a skill that pays off well beyond KS2, right through secondary school essay writing.
Try The Pocket Money Game Free
Help your child practise spelling, maths and reading — and earn real pocket money for every correct answer. 7-day free trial, no card needed.