突然

突然 (tūrán) means 'suddenly' or 'sudden' — describing something that happens without warning. It functions as both adverb and adjective: 他突然走了 ('he suddenly left'), 这件事很突然 ('this matter was very sudden'). Placement is flexible — 突然 can sit before the verb (most common: 他突然哭了 'he suddenly cried') or at the start of a sentence to frame what follows (突然，电话响了 'Suddenly, the phone rang').

English speakers often default to 'suddenly' at sentence end, but in Chinese 突然 rarely comes last. The 然 ending marks 突然 as a manner word (compare 当然 'of course,' 忽然 'all of a sudden'). For a slightly more written / abrupt feel, use 忽然 (hūrán); they overlap heavily, but 突然 also takes the adjectival role that 忽然 cannot.