"Dw i wedi yfed coffi heno."
Translation:I've drunk a coffee tonight.
It's hard to think of a situation where you would want to say this sentence but I think it's OK grammatically. If you add "too much" I think it sounds more natural, ie "Why aren't you tired?" "Because I've drunk too much coffee tonight".
My problem with the sentence is the article. People don't say, "I've drunk a coffee." They say, "I've drunk coffee" or "I've drunk a cup of coffee."
I typed 'dronk' instead of 'drunk' and it tells me 'you used the wrong word'. There is no such word as 'dronk' in English so i think it should say 'you have a typo in your answer'. That is usually what happens.
In English, the past participle of the verb 'drink' is 'drunk', not 'drank'. 'Drank' is the simple past tense:
- I have drunk
- I drank
The two tenses there are different in English, as they are in Welsh.
I said "I have drank coffee today" and it didn't accept it. I don't know if it's just focused on Welsh English or something, but I assume it's dialectal since I'm American.
The standards seem to be 'I have drunk' and 'I drank' in the main varieties of English. A quick search of the web for 'I have drunk' or 'I have drank' or 'drunk vs drank', etc finds several explanations.