The past tense of the verb ‘bite’ is ‘bit’. For example, you would say, ‘Yesterday, the dog bit the mailman.’
However, in some contexts, especially in American English, the past participle form ‘bitten’ is also used. For instance, ‘The mailman has been bitten by the dog.’
Understanding the correct usage of ‘bit’ and ‘bitten’ can help in constructing grammatically accurate sentences.