Phrases, clauses (main & subordinate) and their use in different kinds of sentences (i.e. simple, compound and complex) commonly appear in 11 plus exams.
A phrase is a small group of words that do not make sense on their own.
A clause is a small group of words that does make sense on its own. It contains a subject (noun or pronoun) and a verb and therefore is like a mini-sentence as it is a complete statement. Some clauses can work by themselves as independent clauses. Other clauses, e.g. subordinate or embedded clauses need to be connected to parts of a sentence.
Phrases do not make sense on their own: to the house = phrase / on the floor = phrase / coming home = phrase / when walking = phrase
Independent clauses make sense on their own and create simple sentences: I slept. / Jon ate here. / I like lemons. / Ruby worked.
Using two independent clauses with a conjunction/connective creates a compound sentence: My grandfather was very tall and he worked in the City of London. (the conjunction ‘and’ joins these two independent clauses)
Using an embedded clause creates a complex sentence: The doctor visited, late at night, to treat the fever. (embedded in the sentence and separated by commas)
Using a subordinate clauses creates a complex sentence: (1) When I have finished working, I shall make a milk shake. (clause at the front of this sentence is separated by a comma) (2) Grace would like to meet you, if you have the time. (clause at the end of this sentence is separated by a comma)
Main & Subordinate Clauses