Sentence Structure: Phrases and Clauses

English Language · WAEC and JAMB · SS2 and SS3

The comprehension section asks you to give the grammatical name of an expression and state its function, and that pair of questions is worth real marks every year. The same knowledge keeps your essay sentences varied, which is exactly what the organisation mark rewards.

What you need to know

Every complete sentence needs a subject and a finite verb and must express a complete thought. 'Because the rain started' has both a subject and a verb but is not a sentence, since because leaves the thought hanging.
A phrase is a group of words with NO finite verb, while a clause contains a finite verb. 'In the early morning' is a phrase; 'when the day broke' is a clause.
A main clause makes sense standing alone; a subordinate clause depends on the main clause for its meaning and is introduced by a word such as because, although, when, if, that, who or which.
A simple sentence has one main clause: 'The bell rang.' A compound sentence has two or more main clauses joined by and, but, or, so, for, nor or yet: 'The bell rang and the pupils ran out.'
A complex sentence has one main clause plus at least one subordinate clause: 'When the bell rang, the pupils ran out.' A compound-complex sentence has at least two main clauses and one subordinate clause.
A noun clause does the work of a noun, so it can be the subject or the object of a verb. In 'I know that he is lying', the clause 'that he is lying' is the object of the verb know.
An adjectival clause, also called a relative clause, qualifies a noun and usually begins with who, whom, whose, which or that. In 'The boy who won the prize is my cousin', the clause tells us which boy.
An adverbial clause modifies the verb by giving the time, place, reason, condition, purpose, result or manner of the action. Name the type when you answer: 'adverbial clause of reason', not just 'adverbial clause'.
When WAEC asks for the FUNCTION of a clause, a bare label earns nothing. Say what it does and to which word: 'it qualifies the noun boy' or 'it is the object of the verb know' or 'it modifies the verb ran, stating when'.
An appositive is a noun phrase placed beside another noun to rename it, as in 'Mr Bello, our Mathematics teacher, is retiring'. Its function is to explain or give more information about the preceding noun.
A participial phrase begins with a verb form in -ing or -ed and must attach to the right noun. 'Walking to school, the rain soaked me' says the rain was walking; write 'Walking to school, I was soaked by the rain.'
A comma splice is two complete sentences joined by only a comma: 'The rain started, we cancelled the match.' Repair it with a full stop, a semicolon, or a joining word.
Vary your sentence lengths and types in essays. A page of short simple sentences reads like a primary school composition, while a page of long complex ones loses the reader and usually loses control of punctuation too.
Keep related words close together. 'He donated a desk to the school that was broken' suggests the school was broken; write 'He donated a broken desk to the school.'

Key terms

Clause: A group of words containing a finite verb and its subject, forming part of or the whole of a sentence.
Phrase: A group of words that works as a single unit of meaning but contains no finite verb.
Main clause: A clause that expresses a complete thought and can stand alone as a sentence.
Subordinate clause: A clause introduced by a subordinating word that cannot stand alone and depends on a main clause.
Adjectival clause: A subordinate clause that qualifies a noun or pronoun, usually introduced by who, which, whose or that.
Appositive: A noun or noun phrase placed next to another noun to rename or explain it, normally set off by commas.
Comma splice: The error of joining two independent clauses with only a comma.

Worked examples

Combine these into one complex sentence and name the two clauses: 'The rain started. We cancelled the match.'

Decide which idea is the cause and which is the result. The rain starting is the reason.
Turn the reason into a subordinate clause by putting a subordinating conjunction in front of it: 'Because the rain started'.
Attach the remaining idea as the main clause, and separate the two with a comma because the subordinate clause comes first.
Name the clauses by what they do, not merely by their position.

Answer: 'Because the rain started, we cancelled the match.' - 'Because the rain started' is a subordinate adverbial clause of reason, and 'we cancelled the match' is the main clause.

From the sentence 'The driver, who had been warned twice, ignored the sign', give the grammatical name of the expression in commas and state its function.

Check whether the expression contains a finite verb. 'had been warned' is finite, so it is a clause, not a phrase.
See what kind of word it is attached to. It follows the noun 'driver' and tells us more about him.
A clause that qualifies a noun is an adjectival clause, also called a relative clause.
State the function by naming the exact word it qualifies.

Answer: Grammatical name: adjectival clause (relative clause). Function: it qualifies the noun 'driver'.

The mistake to avoid

Asked for the function of a clause, candidates repeat the name instead: they answer 'it is an adjectival clause' and score nothing, because the examiner wants 'it qualifies the noun driver'. The other common fault is calling any long stretch of words a phrase without first checking whether it contains a finite verb.

In the exam

Answer the grammatical name question in two separate parts and write them on two lines, since the name and the function are marked separately. Always quote the exact word the expression relates to. In your essay, aim for a mix of simple, compound and complex sentences in every paragraph; the organisation mark notices sentence variety.