所以
suǒ​yǐ HSK2

so

suǒ​yǐ so · reason · why
  1. 所 suǒ particle
    [relative]
    Used before a verb to form a noun-like phrase representing the object of the action, meaning "that which" or "what".
  2. 以 yǐ preposition
    because of
    because of; due to; for the reason that

suǒ​yǐ that by which
  1. 所 suǒ particle
    [relative]
    Used before a verb to form a noun-like phrase representing the object of the action, meaning "that which" or "what".
  2. 以 yǐ preposition
    by means of
    to use; by means of; with; using the tool or method introduced

suǒ​yǐ decorum
  1. 所 suǒ
    proper place
    the proper or appropriate place or position (often in the phrase 其所 qí​suǒ)
  2. 以 yǐ preposition
    by means of
    to use; by means of; with; using the tool or method introduced