How do you say have eat in Tamil?

"Have eat" is not a grammatically correct phrase in English, and it doesn't translate directly into Tamil.

To express "have eaten" in Tamil, you would say:

சாப்பிட்டேன் (saappiṭṭēn) - for "I have eaten"

சாப்பிட்டாங்க (saappiṭṭāṅka) - for "They have eaten"

சாப்பிட்டீங்க (saappiṭṭīṅka) - for "You have eaten" (plural or polite singular)

சாப்பிட்டீர் (saappiṭṭīr) - for "You have eaten" (singular, informal)

Note: The word "சாப்பிட்டேன்" (saappiṭṭēn) is the past tense of "சாப்பிடு (saappiḍu)" which means "to eat".