These questions ask whether a relative clause correctly identifies one member or subset from a larger group. You need to preserve that identifying meaning while checking punctuation, relative form and the grammatical role inside the clause.
Test the meaning before the punctuation
Ask whether the listener needs the clause to know which person or thing you mean. If yes, keep the clause attached without commas. In The lamps that use little power last longer, the clause selects particular lamps. By contrast, paired commas would present the same words as an aside about lamps already identified.
| Decision signal | Method |
|---|---|
| The clause selects one person or a subset | Use a defining clause with no surrounding commas: the runners who train here. That can also refer to people in this clause type. |
| The clause selects one thing or subset of things | Use which or that without commas: the path which reaches the lake; the path that reaches the lake. Both forms are standard. |
| The relative form performs the clause action | Keep it because the clause needs a subject: the bell that rings at noon. |
| Another noun performs the action and the antecedent receives it | The object form may be omitted: the film Rosa recommended. Rosa is the subject, and film fills the object gap. |
| A following noun belongs to the antecedent | Use whose: the neighbour whose bicycle vanished. |
Use a removal check only to understand the meaning, not as a punctuation trick. If removing the clause makes the intended identity unclear or changes which members the statement covers, the clause is defining. Then inspect the internal sentence: locate its subject, verb and any object gap before deciding whether a relative form can disappear.
Where the construction can go wrong
| Trap | How to reject it |
|---|---|
| Paired commas are added around information that selects a subset | The commas change the clause into extra information and can change the sentence's meaning. Keep an identifying clause unpunctuated. |
| Only one edge of the clause receives a comma | A defining clause takes neither boundary comma. A single comma can also wrongly divide the subject from its main verb. |
| A subject relative form is removed as though every defining relative allowed omission | Omission depends on role. If the relative form performs the action, deleting it leaves the clause without a subject. |
| An object relative is omitted but an ordinary object pronoun is inserted in its place | The antecedent already fills the understood object position. Adding it or another matching pronoun represents the same thing twice. |
Try it
Several files were stored, but only the damaged files were restored. Choose the sentence that preserves that meaning.
- The files, which were damaged, were restored.
- The files which were damaged were restored.
- The files which were damaged, were restored.
- The files, that were damaged were restored.
Which sentence correctly identifies the alarm that caused the waking?
- The alarm, that woke us, was defective.
- The alarm that woke us was defective.
- The alarm woke us was defective.
- The alarm that it woke us was defective.
Complete the identifying clause with a five-word fragment: Give the parcel to the tenant ___. Use whose, key, opens, and the archive in that order, with no added words.