To sweat or perspire — to produce sweat due to temperature, exertion, or nervousness.
暑くて外に出たらすぐに汗をかいた。
It was hot, and as soon as I went outside I started sweating.
試験中は緊張して手に汗をかいた。
I was so nervous during the exam that my hands sweated.
朝のジョギングでたくさん汗をかいたのでシャワーを浴びた。
I sweated a lot during my morning jog, so I took a shower.
夏は通勤で汗をかくことが多いから着替えを用意している。
In summer I often sweat during the commute, so I keep a change of clothes ready.