他经常喝咖啡用英语怎么说

"He drinks coffee frequently" 用英语说就是 "He is a regular coffee drinker."
"Regular" 这个词来源于拉丁语 "regulāris"，意思是 "按规则的" 或 "经常的"。
例句1:
He's a regular at the coffee shop. 他是咖啡店的常客。
例句2:
He starts every morning with a cup of coffee, he is a regular coffee drinker. 他每天早上都要来一杯咖啡, 他是个常喝咖啡的人。
例句3:
I see him at the coffee shop every morning, he must be a regular. 我每天早上都在咖啡店看到他，他肯定是常客。