as long as

as long as — idiom

1. used to state a condition that must be satisfied before something else can happe

1.慣用語B1
釋義

used to state a condition that must be satisfied before something else can happen or be true.

例句

You can borrow my car as long as you bring it back by six o'clock, Eitan.

condition stated after the main clause

Nikhil agreed to help with the move as long as we paid for the petrol.

同義詞
  • provided that

    more formal; common in written English and official contexts

  • provided

    shorter form of 'provided that', also formal

  • on condition that

    very formal; often used in contracts and legal documents

反義詞
  • unless

    expresses the opposite idea — something will happen only if the condition is NOT met

文法句型

as long as + present simple clause

用法筆記

When referring to future time, use the simple present tense after 'as long as', not 'will' or 'would'. The condition clause can come either before or after the main clause — a comma is needed when it comes first.

常見錯誤

❌You can borrow the book as long as you will return it by Friday.
✅You can borrow the book as long as you return it by Friday.
💡Use the simple present (not 'will') after 'as long as' when talking about the future.
❌As long as you study hard, so you will pass the exam.
✅As long as you study hard, you will pass the exam.
💡Do not add 'so' or 'then' to the main clause when 'as long as' already introduces the condition.

2. used to introduce a fact that is already known to be true and which serves as th

2.慣用語B2
釋義

used to introduce a fact that is already known to be true and which serves as the reason for a statement or request — unlike Sense 1, what follows 'as long as' describes a given situation, not a hypothetical condition that needs to be satisfied.

例句

As long as you're already going to the shop, could you pick up some milk, Lucía?

presenting a reason while making a request

As long as Soraya and Iris were already at the market, they decided to buy fresh fish for dinner.

同義詞
  • since

    neutral and widely used in both speech and writing

  • given that

    slightly more formal; common in academic and professional contexts

  • inasmuch as

    very formal; mainly used in legal or academic writing

文法句型

as long as + clause giving a reason

用法筆記

In this sense, the clause after 'as long as' describes a fact that the speaker already knows to be true — not a hypothetical condition. This distinguishes it from Sense 1. The sense is more common in spoken English than in formal writing.

常見錯誤

❌As long as it rains, we will stay inside' (meaning 'because it is raining').
✅As long as it is raining, we might as well stay inside.
💡In this sense, what follows 'as long as' must be treated as a known fact, not a pure hypothetical. Using 'might as well' or 'since' makes the causal meaning clearer.