Incorrect spelling, explanation: this form is incorrect because eat plus ing is not eatting but eating; there is no reason to double the consonant. We do double the last consonant when adding a suffix in case of a consonant-vowel-consonant situation at the end of the word. Here we have vowel-vowel-consonant so we don’t double the last consonant. Therefore the correct form is eating.

Correct spelling, explanation: there is just one t in eating because this is a verb eat with suffix -ing. The only situation where we need to double the last consonant is when it’s preceded by a consonant and vowel. Here there are two vowels, so it’s not eatting but eating.

Definition of eating:
verb, gerund form of eat, to ingest, to consume
Look, your dog is eating something strange!
I love eating cheese but I’m mildly allergic to dairy.

Incorrect spelling

Incorrect spelling

Incorrect spelling