unless

unless — conjunction

1. Introduces a condition that must NOT happen for the main statement to be possibl

1.連接詞B1
釋義

Introduces a condition that must NOT happen for the main statement to be possible — the main part of the sentence holds true in every situation except when this condition exists.

例句

Élise will not go to the beach tomorrow unless the storm has passed by morning.

not…unless + present perfect

Unless a major earthquake destroys the building, the family reunion will happen on Sunday.

Unless + clause at start of sentence

同義詞
  • if not

    The most common alternative; 'unless' is preferred when stating the only exception rather than a general condition

  • except when

    More formal and less frequent; places heavier emphasis on the exceptional nature of the condition

反義詞
  • if

    Presents the condition that makes something happen; 'unless' presents the condition that stops something from happening

文法句型

unless + clause (present tense)

用法筆記

The verb in the unless-clause takes the present tense even when the meaning refers to the future. Unlike 'if not', 'unless' emphasises the one situation that would prevent the main action from happening.

常見錯誤

❌Unless he will call, we will cancel the order.
✅Unless he calls, we will cancel the order.
💡Use present tense, not 'will', after 'unless' when referring to the future.
❌Unless if it rains, the match will go ahead.
✅Unless it rains, the match will go ahead.
💡Do not use 'if' after 'unless'; the two words together are redundant.

unless — preposition