drank / drunk
The past tense versus the past participle.
Drank is the past tense: She drank the water. Drunk is the past participle after a form of have or a form of be: She has drunk the water. She was drunk. Do not use She has drank.
Examples
UseHe drank the coffee.
UseHe has drunk the coffee.
AvoidHe has drank the coffee.