Correct spelling, explanation: this spelling is correct as the adverb is made from the adjective definite. Because of the adjective’s spelling, the correct form is definitely: adverbs are made by adding the suffix -ly to an adjective. This suffix starts with a consonant, so e at the end of definite remains. This is why definitly is an incorrect spelling.

Definition of definitely:
adverb, in a clear, definite way
It is definitely wrong to steal anything from anyone.
– Are you sure? – Definitely!

Incorrect spelling, explanation: we should spell this word definitely as to create this adverb we add suffix -ly to adjective definite. E ending the word is dropped with suffixes starting with a vowel, but here -ly starts with a consonant, so the final form is definitely, not definitly.

Incorrect spelling

Incorrect spelling

Incorrect spelling

Incorrect spelling

Incorrect spelling

Incorrect spelling

Incorrect spelling

Incorrect spelling