Definition

1. Conjunction:
   • The reason why; that is why; if... it is because...: Used to introduce the cause or reason for a previously stated or implied situation or fact. It sets up a logical explanation, often paired with "là vì" (is because) or "bởi vì" (because) in the following clause.

Usage Examples

• Conjunction:
  • Sở dĩ họ từ chối là vì họ bận quá. (The reason they refused is because they were too busy.)
  • Sở dĩ tôi đến muộn là do kẹt xe. (That I am late is because of the traffic jam.)
  • Sở dĩ cô ấy thành công bởi vì cô ấy rất chăm chỉ. (The reason she is successful is because she is very hardworking.)

Advanced Usage

• "Sở dĩ... là vì...": The standard correlative structure meaning "The reason why... is because...".

  • Sở dĩ dự án thất bại là vì thiếu kế hoạch. (The reason the project failed is because of a lack of planning.)

• "Sở dĩ... là do...": An alternative structure where "do" introduces the cause.

  • Sở dĩ anh ấy buồn là do tin đó. (That he is sad is due to that news.)

Variants and Related Words

• Bởi vì (conj): because. (A simpler, more direct causal conjunction.)
• Vì (conj): because, for. (The most common and basic causal conjunction.)
• Nguyên nhân (n): cause, reason. (The noun for "reason".)

Synonyms

• The reason why: Indicates an explanation is being given.
• That is why: Used to introduce a resulting explanation.
• If... it is because...: Used in a conditional-explanatory sense.

Related Idioms

• Sở dĩ như vậy: The reason it is like that.

  • Anh muốn biết sở dĩ như vậy? (Do you want to know the reason why it is like that?)

• Chính vì thế sở dĩ...: Precisely for that reason, that is why...

  • Chính vì thế sở dĩ chúng tôi phải thay đổi. (Precisely for that reason, we had to change.)

1. If, that is why
   • Sở dĩ họ từ chối là vị họ bận quá
     If they refused, it was because they were very busy