This KS2 English quiz will challenge you on complex sentences. You can create complex sentences by joining two simple sentences together. If you take these two sentences: 'Alec was happy' and 'It was Alec's birthday', you can create this complex sentence: 'Alec was happy because it was his birthday.' If you join the sentences with 'and', 'but', 'so', 'yet', 'nor', 'or' or 'for', you've made a compound sentence, rather than a complex sentence.
Some other words that denote a complex sentence are ‘while’, ‘although’, ‘until’ and ‘after’. Make sure you know the difference between a compound and complex sentence before moving onto the next quiz.