Sentence Construction and Synthesis

🟢 Lite — Quick Review (1h–1d)

Rapid summary for last-minute revision before your exam.

Sentence Construction and Synthesis — Quick Facts

The Four Sentence Types:

1. Simple sentence — One independent clause: “The teacher marked the scripts.”
2. Compound sentence — Two or more independent clauses joined by a coordinating conjunction (and, but, or, nor, for, yet, so — the acronym FANBOYS helps): “The teacher marked the scripts, and she returned them the following day.”
3. Complex sentence — One independent clause + one or more dependent clauses: “Although she was tired, the teacher marked the scripts.” (Dependent clause introduced by a subordinating conjunction.)
4. Compound-complex sentence — Two or more independent clauses + one or more dependent clauses: “Although she was tired, the teacher marked the scripts, and she prepared the next lesson.”

Key Grammatical Terms:

• Clause — A group of words containing a subject and a verb.
• Phrase — A group of words without either a subject or a verb (or both): on the table, running quickly, to leave.
• Independent/Principal clause — Can stand alone as a complete sentence.
• Dependent/Subordinate clause — Cannot stand alone; needs the main clause to form a complete sentence. (Because it rained, the match was postponed.)

Sentence Synthesis — Joining Sentences: Sentence synthesis means combining two or more short sentences into one grammatically correct, sophisticated sentence. This is a very common WAEC question in Paper 2, Section B (Sentence Transformation).

Three essential synthesis techniques:

1. Using coordinating conjunctions (and, but, or) — The simplest method.
2. Using subordinating conjunctions (because, although, when, if, since, while, after, before, unless, whenever, whereas) — More sophisticated.
3. Using relative pronouns (who, whom, whose, which, that) — For joining sentences about people or things.

⚡ WAEC Exam Tip: In Paper 2, Question 8 (Sentence Transformation), you must transform sentences without changing their meaning. Read both the instruction and the example carefully. The three most common transformation types are: active to passive voice, direct to indirect speech, and simple to compound or complex sentences.

⚡ WAEC Exam Tip: Subject-verb agreement errors are very common and carry heavy penalty. Remember: singular subjects take singular verbs; plural subjects take plural verbs. Watch out for collective nouns (committee, team, jury — usually singular in British English: “The committee has decided”), indefinite pronouns (each, either, neither, one, everyone, nobody — always singular: “Each of the students has submitted his work”), and phrases between subject and verb (together with, as well as, along with do NOT change the number of the subject).

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🟡 Standard — Regular Study (2d–2mo)

Standard content for students with a few days to months.

Sentence Construction and Synthesis — Study Guide

Mastering the Four Sentence Structures

Simple Sentences: The foundation of all English writing. A simple sentence has one principal clause. It can be expanded using adjectives, adverbs, and prepositional phrases, but it remains simple if it contains only one subject-verb unit.

Simple: The boy read the book. / Expanded: The brilliant young boy, who had always loved adventure stories, read the fascinating book with great enthusiasm.*

Compound Sentences: Two independent clauses joined by a coordinating conjunction (FANBOYS: for, and, nor, but, or, yet, so). The comma is placed before the conjunction.

Compound: Emeka passed the examination, but his sister failed.

Note: A semicolon (;) can also join two closely related independent clauses without a conjunction: “Emeka passed; his sister failed.”

Complex Sentences: One independent clause + one or more dependent (subordinate) clauses. The dependent clause can be:

• Noun clause (acts as subject, object, or complement): “What he said surprised everyone.” / “I believe that she is honest.”
• Adverb clause (answers: when, where, why, how?): “Because it rained, we stayed indoors.” / “She smiled when she saw the results.”
• Relative clause (describes a noun using who, whom, whose, which, that): “The student who came first was awarded a scholarship.”

Subordinating Conjunctions — Key Words:

• Time: when, while, as, before, after, until, since, whenever
• Cause/Reason: because, since, as (meaning “because”)
• Condition: if, unless, provided that, in case
• Contrast: although, though, even though, whereas, while
• Purpose: so that, in order that, lest
• Result: so…that, such…that

Relative Clauses — Defining vs Non-Defining:

	Defining (essential)	Non-defining (non-essential)
Commas	No commas	Commas on both sides
Function	Identifies the noun	Adds extra information
Can “that” be used?	Yes	No (use “who”, “which”)
Example	The student who passed received a prize.	Mr Adebayo, who passed last year, now works in Lagos.

⚡ WAEC Exam Tip: Non-defining relative clauses are frequently tested. WAEC examiners expect you to know that commas surround non-defining clauses and that “that” cannot be used with non-defining clauses. “The book which I lost” (defining — no commas) vs “The book, which I lost yesterday, was new” (non-defining — commas).

⚡ Common Mistake: Using “who” for things (only for people) and “which” for people (only for things). “The boy who scored the highest” is correct. “The tree which grew tall” is correct. “The boy which was tall” is wrong.

Sentence Synthesis — Detailed Techniques:

Technique 1: Using Coordinating Conjunctions

Sentence A: The match started. / Sentence B: The rain stopped. Synthesis: The match started, and the rain stopped. OR The match started, but the rain had not stopped yet. OR The rain stopped, so the match started.

Technique 2: Using Subordinating Conjunctions

Sentence A: Chidi studied hard. / Sentence B: He passed the exam. Synthesis: Because Chidi studied hard, he passed the exam. OR Chidi passed the exam because he studied hard.

Technique 3: Using Relative Pronouns

Sentence A: The man is my uncle. / Sentence B: The man spoke to us yesterday. Synthesis: The man who spoke to us yesterday is my uncle. OR My uncle, who spoke to us yesterday, is a lawyer.

Technique 4: Using Participial Phrases (advanced synthesis)

Sentence A: The teacher entered the class. / Sentence B: The students stood up. Synthesis: Entering the class, the teacher was greeted by standing students. / The students stood up as the teacher entered the class. (Using -ing participles to connect ideas smoothly.)

Technique 5: Using Infinitive Phrases

Sentence A: She wanted to pass the exam. / Sentence B: She read every night. Synthesis: She read every night to pass the exam. (The infinitive phrase expresses purpose.)

⚡ WAEC Exam Tip: In synthesis questions, do not add or remove information — preserve the original meaning. Also, do not use “and” when the logical relationship between the two ideas is one of cause, condition, or contrast (use because, if, although instead). Using the wrong conjunction changes the logical relationship and is penalised.

⚡ Common Errors in Sentence Construction:

1. Run-on sentences (fused sentences): “The bell rang we went home.” → Fix: add a period, semicolon, or conjunction.
2. Comma splice: “The bell rang, we went home.” → Fix: add a conjunction after the comma, or replace with a semicolon, or split into two sentences.
3. Sentence fragments: “Running quickly.” → Fix: add a subject and verb: “She was running quickly.”
4. Misplaced modifiers: “He almost passed all his exams.” (suggests he did not actually pass) → Fix: “He almost passed all his exams” is ambiguous; better: “He passed almost all his exams.”
5. Dangling modifiers: “Walking to school, the rain started suddenly.” (the rain was not walking to school) → Fix: “Walking to school, we were caught in sudden rain.”
6. Double negatives: “She doesn’t have nothing” → Fix: “She doesn’t have anything” or “She has nothing.”

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🔴 Extended — Deep Study (3mo+)

Comprehensive coverage for students on a longer study timeline.

Sentence Construction and Synthesis — Comprehensive Notes

The Deep Grammar of English Sentences

Clause Elements — The Building Blocks:

Every English clause is built from a combination of these elements:

Element	Function	Example
S (Subject)	The doer or topic	The dog
V (Verb)	The action or state	barked
O (Object)	The receiver of the action	the postman
C (Complement)	Completes the subject or object	is brown (subject complement); made him captain (object complement)
A (Adverbial)	Circumstances: time, place, manner, cause	yesterday, in the garden, quickly

Sentence Patterns in English:

• SVO: The cat caught the mouse.
• SVA: She lives in Lagos.
• SVC: She is a teacher. / The news made her sad.
• SVOA: She put the book on the table.
• SVOO: She gave the boy a gift. / He told us a story.
• SVOC: They elected him president.

⚡ WAEC Exam Tip: Many WAEC grammar questions test your knowledge of these patterns. For example, SVOO sentences (with two objects) can be transformed: “She gave the boy a gift” → “She gave a gift to the boy.” The indirect object (recipient) becomes the object of the preposition “to.” This transformation is a common WAEC sentence transformation question.

Tense Consistency — One of the Most Commonly Tested Areas:

In complex and compound sentences, WAEC examiners frequently test your ability to maintain tense consistency, especially when:

1. Reporting speech (direct to indirect): “He said, ‘I am coming.’” → “He said that he was coming.” (present simple → past simple; present continuous → past continuous; will → would; can → could; shall → should.)
2. Using past participles correctly: Many candidates confuse irregular past participles. Drill these common ones: written, spoken, broken, taken, driven, swum, begun, rung, grown, flown, known, shown, hidden, ridden, drawn, fought, bought, taught, caught, brought, thought, heard, felt, kept, slept, left, built, sent, spent, lent, sent, hurt, put, cut, shut, hit.
3. Sequence of Tenses (Backshifting): When the main clause is in the past tense, dependent clauses generally shift back one tense:
   • If she is here, I will tell her. → (future simple in conditional) → In past reporting: If she was here, I would tell her (but this is the subjunctive; the standard is If she were here, I would tell her.)
   • “I will call you when I arrive.” → In past: “I told him I would call him when I arrived.”

Advanced Synthesis Techniques:

1. Using Absolute Phrases: An absolute phrase consists of a noun + a participle, with no formal connection to the main clause (no conjunction needed).

Sentence A: The match was finished. / Sentence B: The crowd went home. Synthesis: The match finished, the crowd went home. (absolute phrase — more elegant than a simple conjunction)

2. Using Appositive Phrases: An appositive renames or explains the noun beside it.

Sentence A: Dr Nnamdi is a renowned cardiologist. / Sentence B: Dr Nnamdi has been appointed Minister of Health. Synthesis: Dr Nnamdi, a renowned cardiologist, has been appointed Minister of Health.

3. Using Participial Constructions:

Sentence A: The student completed the exam. / Sentence B: The student left the hall quietly. Synthesis: Completing the exam, the student left the hall quietly. OR Having completed the exam, the student left the hall quietly. (The perfect participle “having completed” emphasises that the action was finished before the next one began.)

4. Combining Conditionals:

Sentence A: You work hard. / Sentence B: You will succeed. Synthesis: If you work hard, you will succeed. (First conditional — real future possibility)

Learn the four conditional forms — WAEC almost always tests at least one:

Type	Structure	Time Reference	Example
Zero	If + present simple, present simple	General truths	If you heat water, it boils.
First	If + present simple, will + verb	Real future possibility	If it rains, I will stay home.
Second	If + past simple, would + verb	Hypothetical present/future	If I had money, I would travel.
Third	If + past perfect, would have + past participle	Hypothetical past	If I had studied, I would have passed.

⚡ WAEC Past Question Patterns for Sentence Construction:

From 2018–2024 WAEC papers, the following question types appear regularly in Paper 2:

1. Sentence Transformation (Question 8):

• “Change from active to passive.” — E.g.: “The teacher marked the papers” → “The papers were marked by the teacher.”
• “Change from direct to indirect speech.” — E.g.: “‘I will come tomorrow,’ she said.’” → “She said that she would come the following day.”
• “Join with: although / because / when / since / so that…”

2. Synthesis (combining sentences):

• Join using a relative pronoun: “The house. The house belonged to my grandfather.” → “The house which belonged to my grandfather…”
• Join using a participial phrase.
• Join using a noun clause.

3. Error Identification (Question 4 or 5): Candidates must identify the grammatically incorrect option in a four-choice multiple choice. Common errors:

• Subject-verb disagreement (Emeka, together with his brothers, was present — should be “were”? No, actually: “Emeka, together with his brothers” — the subject is Emeka (singular), so “was” is correct. But: “Emeka and his brothers were present.”)
• Wrong tense or aspect (She has went — wrong; should be “has gone”)
• Wrong preposition (borrow from — wrong; should be “borrow from” is correct, but “lend to” is the opposite direction; angry with someone, not “angry at”)
• Double negative (can’t hardly, doesn’t have no)

4. Concord (Agreement) — Frequently Tested: Rules to master:

• Either…or / Neither…nor: Verb agrees with the nearer subject: “Neither the students nor the teacher was aware.” (teacher is singular — singular verb.) / “Neither the teachers nor the students were aware.” (students is plural — plural verb.)
• Each / Every / Everyone / Nobody / Someone / One: Always singular: “Each of us is responsible.”
• Plural nouns with singular verbs (in British English): Mathematics is, Physics is, news is, politics is, athletics is — these are all uncountable/singular in form but plural in meaning; British English treats them as singular.
• Police, clergy, cattle: Plural in meaning; plural verb: “The police are investigating.”
• The + adjective (referring to a group of people): “The rich are blessed” (the rich = rich people; plural verb).

5. Conditionals in Gap-Fill: “If Adaeze ___ (study) hard, she ___ (pass) her exams.” Answer: studies, will pass. (First conditional: if + present simple, will + infinitive.)

⚡ Final WAEC Strategy: For sentence transformation questions, always read the given sentence twice before writing your answer. Identify the key elements (subject, verb, object) and the transformation required. Write your answer, then check: (1) Have I preserved the original meaning? (2) Is the grammar correct? (3) Does the result make a complete, natural sentence? For synthesis, the single most effective strategy is to identify the logical relationship between the two short sentences — if it is cause-effect, use because/so; if it is contrast, use although/but; if one sentence describes a person or thing, use a relative pronoun. Practice past WAEC questions under timed conditions — speed and accuracy both matter.