until, by

How to use まで (made) and までに (by)

 

I'm sorry I'm late.
  • 5時まで仕事をします。
    5-ji made shigoto o shimasu.
    I will work tunil 5 o'clock.
  • 5時までにメールします。
    5-ji made shigoto o shimasu.I will work tunil 5 o'clock.
    I will e-mail you by 5 o'clock.