half-hour

half-hour — noun

1. A length of time that lasts 30 minutes.

1.名詞A1
釋義

A length of time that lasts 30 minutes.

例句

The train from Taipei arrives in half an hour.

half an hour — common fixed phrase

Christopher waited for half an hour outside the library.

同義詞
  • 30 minutes

    more formal and exact; preferred in schedules and written instructions

  • half an hour

    the most common conversational form in both British and American English

反義詞
  • hour

    a period twice as long

文法句型

half an hour

a half hour

every half hour

half an hour + verb

常見錯誤

❌I will be back in half hour.
✅I will be back in half an hour.
💡The indefinite article 'an' is required before 'hour' in this fixed expression.
❌The movie lasts for half of hour.
✅The movie lasts for half an hour.
💡Use 'half an hour' or 'a half hour', not 'half of hour'.

2. The time exactly 30 minutes past the start of an hour, used when telling when ev

2.名詞A2
釋義

The time exactly 30 minutes past the start of an hour, used when telling when events happen rather than how long they last.

例句

The bus comes at the half-hour, so the next one is at half past three.

at the half-hour — scheduled-event time expression

Aoi promised to call her mother on the half-hour after work.

同義詞
  • half past

    preferred in British-influenced time-telling; more common in speech than 'the half-hour'

  • thirty past

    used in American English time-telling; a direct alternative

反義詞
  • on the hour

    the starting point of an hour, the opposite clock position

文法句型

at the half-hour

on the half-hour

past the half-hour

常見錯誤

❌The train leaves on every half hour.
✅The train leaves on the half-hour.
💡Use the definite article 'the' when referring to the 30-minute mark of each hour.
❌I will arrive at half-hour past two.
✅I will arrive at half past two.' or 'I will arrive at the half-hour.
💡Do not combine 'half-hour' with 'past' like that.