Reduced Relative Clauses

What Are Reduced Relative Clauses?

A reduced relative clause is a shortened version of a full relative clause where the relative pronoun (who, which, that) and the auxiliary verb 'be' are removed. This reduction creates more concise, elegant sentences while maintaining the same meaning. Reduced clauses are preferred in formal, academic, and professional writing because they eliminate unnecessary words and create a more sophisticated style.

Active Participle Clauses (Present Participle: -ing)

Active participle clauses use the present participle (-ing form) to replace active voice relative clauses. You can reduce a relative clause to a present participle clause when the full clause contains a continuous tense (is doing, was doing) or describes an ongoing action or characteristic. The subject performs the action actively.

Noun + verb-ing + (rest of clause)

Passive Participle Clauses (Past Participle: -ed/-en)

Passive participle clauses use the past participle (-ed or -en form for irregular verbs) to replace passive voice relative clauses. You can reduce a relative clause to a past participle clause when the full clause contains a passive construction (is done, was done). The subject receives the action rather than performing it. This is extremely common in formal writing and academic texts.

Noun + past participle + (rest of clause)

Infinitive Clauses (to + verb)

Infinitive clauses use 'to + base verb' to replace relative clauses that express future actions, purposes, possibilities, or obligations. This reduction is common after ordinal numbers (first, second, last), superlatives (best, only), and expressions of necessity or possibility. Infinitive clauses often indicate something that will happen, should happen, or can happen.

Noun + to + base verb

Complete Transformation Rules

To reduce a relative clause correctly, follow these systematic steps to identify the clause type and apply the appropriate transformation. Understanding these rules prevents common errors and ensures grammatical accuracy.

Common Mistakes for Indian Learners

This creates ungrammatical sentences because English requires either the present participle (-ing) or past participle (-ed/-en) in reduced clauses.

A critical error is using the present participle (-ing) when the past participle is needed (or vice versa). This happens when learners don't distinguish between active and passive voice. If the subject performs the action, use present participle. If the subject receives the action, use past participle.

Infinitives should only be used after ordinal numbers (first, last), superlatives (best, only), or to express future/purpose. They cannot replace ongoing or completed action clauses.

A dangling participle occurs when the participle phrase is not placed immediately after the noun it modifies, or when the subject that performs the action is missing or unclear. This creates ambiguity or absurd meanings. In English, the participle phrase MUST come right after the noun it describes.

Not all relative clauses can be reduced. Only clauses containing 'is/are/was/were + verb-ing', 'is/are/was/were + past participle', or 'will/should/can + verb' can be reduced.

Reduced Clauses in Formal and Academic Writing

Reduced relative clauses are a hallmark of sophisticated, formal writing. They appear extensively in academic papers, research articles, legal documents, government reports, and essays (IELTS, TOEFL, CAT, ). Examiners and evaluators expect B2+ level writers to use reduced clauses to demonstrate grammatical range and conciseness. Over-reliance on full relative clauses makes writing sound repetitive and elementary.

Indian frequently test reduced relative clauses in sentence correction, error detection, and reading comprehension questions. CAT Verbal Ability, CSAT English Comprehension, and CGL English sections all expect test-takers to identify correct reductions and spot dangling participle errors.

Practice Exercises

Quick Revision Summary

These ten rules cover all critical aspects of reducing relative clauses correctly. Memorize these for exam success and formal writing proficiency.