вначале

erst

at first, first — at the beginning

• Я вначале его не узнал.

  I didn't recognize him at first.

  Tatoeba · heccele · CC BY 2.0 FR

• Вначале я думал, что болею.

  At first, I thought I was sick.

  Tatoeba · odexed · CC BY 2.0 FR