What is the difference between "を" and "は"? Can I say both "お茶を飲みます。" and "お茶は飲みます。"?


I'm aware that I can say "お茶を飲みます。" (with the particle "を") to convey the
meaning "I drink tea." in the sense of indicating that an action is taking
place.

However, I'd like to know if I can also say "お茶は飲みます。" (with the particle "は")
to convey "I drink tea." in the sense of "Drinking tea is something I
generally do." If not, what would I say to distinguish between the two
meanings?

(This question was inspired by the Duolingo exercise at
<https://www.duolingo.com/comment/26545844>. Surprisingly, I can't find any
articles directly comparing "を" and "は".)




To say "drinking tea is something I generally do", you can use 普段 with
お茶を飲みます: (私は)普段お茶を飲みます. This is perfectly natural.

However, if you instead use は, like (普段)お茶は飲みます, it strongly implies that you
like tea but hate some of others. Because of the reason, a sentence like
お茶はのみます is often used with another sentence that explains what the others. For
example, you can say "お茶は飲みますがコーヒーは嫌いです" and "お茶は飲みますが、家で飲むのはそれだけですね".

