Tri Duc English - Unit 69 🔄 TRI ĐỨC ENGLISH 2026 • Pre-Intermediate UNIT 69 PREFIXES: CHANGING MEANING LÝ THUYẾT TỪ VỰNG A. With adjectives (Tiền tố với tính từ) Prefixes, e.g. un- , dis- , im- , can be added to some adjectives to give the opposite meaning. happy unhappy possible impossible regular irregular honest [tells the truth] dishonest correct [right ✔] incorrect legal [allowed by law] illegal • Dan used all the milk but said he didn't; he's very dishonest . • I got eight answers right, but two were incorrect . • It's illegal in the UK to ride a motorbike without a helmet. B. un- Of the prefixes above, un- is the most common, and appears in a number of adjectives. • This chair is incredibly uncomfortable . • It was unnecessary for them to wait for us. • Xerxes – that's a very unusual name. [different, not common or ordinary] • I won the game; it was completely unexpected . [I didn't think I was going to win] • Marsha's hat is u...