Drank vs. Drunk

it is drank because it is formal

the answerer-
Thank you. I will write it accordingly.

I'm not clear on the "formal" though. I'm aware of active and passive; past, present, future, past perfect; future perfect; indicative; and subjunctive.

What is the meaning of formal ?

The grammatical answer is "drunk" which is the past participle and is used with the auxilliary verb "to have". "Drank" is not used when the verb "to have" is present.

But note that conversational English often strays from prescriptive grammatical rules. Written English tends to follow such rules except in reported speech.

fresco-
Thank you.

Douglas Adams - Hitchhikers Guide to the Galaxy

"The past participle 'drank' is still in standard spoken use in some parts of the US and Canada, but it is seldom seen in print."

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