Complete Grammar Syllabus (145 Units)

Grammar Mastery

Comprehensive reference, real-world IELTS band-boosting tips, clear structural formulas, and interactive short quizzes for intermediate to advanced English learners.

Relative Clauses (Defining vs Non-defining)

Combining clauses with who, which, that, whose, and where. Distinguishing defining (essential) and non-defining (extra information with commas) relative clauses.

Core Structure & Formula

Defining (Type 1, No commas): The lecturer who/that teaches statistics is very approachable.

Non-defining (Type 2, Commas required, No "that"): My colleague Sofia, who lives in Lisbon, is a data analyst.

Possession: whose + noun (The passenger whose luggage was delayed)

Place: where (The campus where we studied)

Commenting on whole clause: , which (The flight was delayed, which annoyed everybody)

AType 1 (Defining) vs Type 2 (Non-defining)

Type 1 defines WHICH person/thing is meant. Type 2 gives extra non-essential details and MUST have commas.

•Type 1: The hostel that you recommended was excellent. (specifies which hostel; that allowed, no commas)

•Type 2: We stayed at the Riverside Hostel, which a colleague recommended. (already identified; commas needed, 'that' forbidden)

•Farid, who speaks Arabic and Spanish, works as a translator.

BCommenting on a whole sentence with ", which"

Use ', which' (never ', what') to add a comment about the entire preceding sentence.

•Farid got the promotion, which surprised everybody. (which = the fact that he got the promotion)

•The conference was cancelled, which was a shame. (not what was a shame)

IELTS Band 7–9 Exam Impact

Non-defining relative clauses and prepositional relative clauses (e.g. "without which", "in which") demonstrate advanced syntactic complexity.

Common Candidate Errors

✗ My mother, that lives in Lyon, is visiting me.

✓ My mother, who lives in Lyon, is visiting me.

Never use 'that' in non-defining relative clauses (with commas).

✗ He arrived late, what annoyed the examiner.

✓ He arrived late, which annoyed the examiner.

Use 'which' (not 'what') to refer back to a whole clause.

Unit 92 Interactive Short Quiz

Test your understanding with 3 verified practice exercises.

Question 1 of 3

My colleague Sofia, ______ lives in Lisbon, is a data analyst.

Question 2 of 3

We assisted some passengers ______ luggage had been delayed.

Question 3 of 3

The conference was cancelled at the last minute, ______ was a real inconvenience.