3. thinkable 4. l. legal 5. polite 6. im. possible - невозможно 7. usual 8.mature We often add the prefix un- to a word to make it ne the word starts with I, m, p or r, we often use a different a) im- + m or p perfect -> imperfect b) ir- + r rational -> irrational c) il- + 1 literate -> illiterate