Choose the option that has a different stress pattern from the others.

Analyze the question: We need the word whose primary stress falls on a different syllable from the other three. Let's mark the stress in each word.

Concept: In English, stress is placed on a particular syllable. Words ending in -tion take the stress on the syllable just before the suffix. Words in -ity or -ability also take stress on the syllable before the ending, though longer words may carry stress further back.

Stress for each word:

• A. ability = a-BIL-i-ty → stress on the 2nd syllable
• B. registration = reg-is-TRA-tion → stress on the 3rd syllable
• C. quadruplicate (verb: /kwɒˈdruːplɪkeɪt/) = quad-RU-pli-cate → stress on the 2nd syllable
• D. revivalist = re-VI-val-ist → stress on the 2nd syllable

Compare:

• ability: 2nd syllable
• registration: 3rd syllable
• quadruplicate: 2nd syllable
• revivalist: 2nd syllable

Three words (A, C, D) are stressed on the 2nd syllable. Only registration is stressed on the 3rd syllable, so it is the odd one out.

Exam tip: For words ending in -tion, -sion, -ic, -ical, the stress usually falls on the syllable immediately before the ending (e.g., reg-is-TRA-tion, e-du-CA-tion). In "odd one out" stress questions, mark the stressed syllable number for every option and spot the one that doesn't match.