reason

/ˈriːzn/ (bre, ipa) · /ˈriːzn/ (ame, ipa) · /ˈrē-zᵊn/ (ame, mw) · /ˈriː.zən/ (bre, ipa) · /ˈriː.zən/ (ame, ipa)

reason — noun

1. something that explains why a particular event, situation, or action happened, o

1.名詞A1
釋義

something that explains why a particular event, situation, or action happened, or why someone behaves or feels a certain way.

例句

Obi gave his teacher a simple reason for being late: the bus broke down.

reason + for + noun phrase / -ing

The main reason why Wei moved to Taipei was the job offer at the hospital.

reason + why + clause

同義詞
  • cause

    focuses on what directly makes something happen; more scientific/neutral than 'reason'

  • motive

    a reason for doing something, especially one kept hidden or involving personal gain

  • explanation

    a statement that makes something clear; broader than 'reason'

反義詞
  • result

    the outcome, rather than the cause or explanation

  • effect

    what happens because of something, not the reason why

文法句型

reason + for + noun/-ing

reason + why + clause

reason + that + clause

the reason...is that...

用法筆記

Followed by for (reason for something), why (reason why…), or a that-clause (the reason is that…). Unlike 'cause', 'reason' focuses on the explanation offered by a person rather than a direct physical cause.

常見錯誤

❌The reason of the accident is still unknown.
✅The reason for the accident is still unknown.
💡use 'reason for', not 'reason of'.
❌The reason is because the train was delayed.
✅The reason is that the train was delayed.
💡'the reason is because' is considered redundant.

2. a formal phrase used in legal or official writing to mean 'because of' a particu

2.名詞B2
釋義

a formal phrase used in legal or official writing to mean 'because of' a particular fact or situation.

例句

The defendant was found not guilty by reason of mental illness.

by reason of + noun phrase (formal/legal)

By reason of her age, Mrs. Chen was excused from jury duty.

同義詞
  • because of

    the everyday equivalent; much more common in speech and informal writing

  • due to

    semi-formal alternative, common in both written and spoken English

  • owing to

    slightly formal, often used to explain a positive or neutral outcome

文法句型

by reason of + noun phrase

用法筆記

Used almost exclusively in formal, legal, or official writing. In everyday conversation, use 'because of' or 'due to' instead.

常見錯誤

❌By reason of the rain, we stayed inside.' (too formal for casual speech)
✅Because of the rain, we stayed inside.
💡reserve 'by reason of' for formal or legal contexts.

3. the ability that humans have to think clearly, use logic, form sensible opinions

3.名詞B2
釋義

the ability that humans have to think clearly, use logic, form sensible opinions, and tell right from wrong.

例句

Beatriz used her reason to figure out which offer was the best deal.

uncountable, no article

Humans are unique among animals in their power of reason.

同義詞
  • logic

    focuses on strict rules of reasoning; more technical than 'reason'

  • rationality

    the quality of being based on reason; more abstract and formal

  • sense

    practical, everyday good judgment; less formal than 'reason'

反義詞
  • emotion

    feeling, as opposed to logical thinking

  • madness

    loss of mental capacity, the opposite of sound reason

文法句型

reason + verb

with/without reason

用法筆記

Uncountable and usually used without an article ('reason', not 'a reason'). Frequently appears in fixed expressions: 'lose one's reason', 'power of reason', 'without reason'. Distinguish from sense 1 ('a reason' = a specific explanation).

常見錯誤

❌He used a reason to solve the problem.' (countable form)
✅He used reason to solve the problem.
💡this sense is uncountable; it means logical thinking ability, not a specific explanation.

4. within limits that most people would consider sensible, fair, and acceptable — n

4.名詞B2
釋義

within limits that most people would consider sensible, fair, and acceptable — not going too far.

例句

You can spend whatever you like on the party, within reason.

fixed phrase at end of sentence

The landlord said we could decorate the apartment within reason.

同義詞
  • sensibly

    adverb form; 'within reason' is a fixed phrase while 'sensibly' is a free adverb

  • moderately

    suggests staying within middle limits; slightly more formal

反義詞

文法句型

within reason

用法筆記

Always appears as the fixed phrase 'within reason' after a statement of permission or possibility. Cannot be modified (*within reasonable). Often implies an unspoken limit that the speaker and listener both understand as sensible.

常見錯誤

❌You can stay out late within reasonable.
✅You can stay out late within reason.
💡the fixed form is always 'within reason', not 'within reasonable'.

reason — verb