강해요 · 강했어요 · 강한 (+noun)
to be strong, to be powerful; to be intense
Example
오늘은 바람이 강하게 불어서 추워요.
The wind is blowing hard today, so it's cold.
Word parts
강 strong
Literally 'strong, powerful'.
Good to know
For physical strength in casual speech, 힘이 세다 is more natural than 강하다.