Modal verbs

• 10 Modal verbs

  10.1

  can 与 could (能力、请求)

  

  

  can 表示能力或可能; could 是 can 的过去式, 也用于更客气的请求。情态动词后面都跟动词原形。

  我I 会can 游泳swim.

  Eu sei nadar.

  她She 会could 读read 在at 四岁four.

  Ela sabia ler aos quatro anos. (Capacidade no passado)

  能Could 你you 帮help 我me 请, please?

  Poder me ajudar, por favor? (Pedido educado)

  Atenção

  • 情态动词后用原形: ~~can to swim~~ ✗ → can swim ✓。
  • 否定: cannot / can't, could not / couldn't。

  10.2

  should (建议)

  should 表示建议或"应该"。

  你You 应该should 看see 一位a 医生doctor.

  Você deveria ir ao médico.

  我们We 不应该shouldn't 浪费waste 水water.

  Não devemos desperdiçar água.

  注意 should 给的是建议, 语气比 must 委婉; 后面同样跟动词原形。

  10.3

  must 与 have to (义务)

  Ambos expressam "obrigação":

  • must: 多表示说话人觉得很重要, 或规则。
  • have to: 多表示外部要求(规定、客观需要)。

  你You 必须must 系wear （冠词）a 安全带seatbelt.

  Você deve usar o cinto de segurança.

  我I 不得不have to 起床get up 早early.

  Preciso acordar cedo.

  Atenção

  • mustn't = "禁止": You mustn't smoke here. (这里禁止吸烟。)
  • don't have to = "不必": You don't have to come. (你不用来。)
  • Atenção: significados opostos: um é "proibido", outro é "não necessário".

  Erros Comuns

  • ❌ ~~You must to wear a helmet.~~ → ✓ You must wear a helmet. — 所有情态动词(can / could / should / must)后面直接跟原形, 永远不加 to。
  • ❌ ~~She musts study harder.~~ → ✓ She must study harder. — 情态动词没有第三人称 -s。
  • ❌ 想说"你不必来"却说 ~~You mustn't come.~~ → ✓ You don't have to come. — mustn't 是"禁止", don't have to 才是"不必", 意思正好相反。
  • ❌ ~~Yesterday I must work late.~~ → ✓ Yesterday I had to work late. — must 没有过去式, 过去的义务用 had to。

Todos os tópicos · Gramática Inglesa · Nível A2