1. Aren't I pretty?
2. Ain't I pretty?
3. Am I not pretty?
4. I'm pretty, aren't I?
5. I'm pretty, ain't I?
6. I'm pretty, am I not?
-------------------------------
Are they all grammatical?
Only 3 and 6 are right. However, they sound awkward to many of us -- so we just avoid saying it.
We could say,
Don't you think I'm pretty?
I think I'm really pretty today.
Yes, all of the sentences you provided are grammatically correct. They differ slightly in terms of style and formality.
1. "Aren't I pretty?" - This is a grammatically correct question formed by using the contraction "aren't" (are not) with the subject pronoun "I" and the adjective "pretty."
2. "Ain't I pretty?" - While the contraction "ain't" (am not, is not, are not) is widely used in informal speech, it is considered nonstandard and should be avoided in formal writing. However, it is still grammatically correct in this sentence.
3. "Am I not pretty?" - This sentence uses the full form of the verb "am" with the subject pronoun "I" and the adjective "pretty." It follows a formal structure and is grammatically correct.
4. "I'm pretty, aren't I?" - This sentence uses the contraction "I'm" (I am) with the adjective "pretty" and the tag question "aren't I" to seek confirmation. It is grammatically correct and commonly used in informal and conversational contexts.
5. "I'm pretty, ain't I?" - Similar to sentence #2, this sentence uses the contraction "ain't" instead of "aren't" as a colloquial expression. It is grammatically correct but more informal than the previous sentence.
6. "I'm pretty, am I not?" - This sentence uses the full form of the verb "am" with the subject pronoun "I" and the adjective "pretty." It also includes the tag question "am I not" for confirmation. This is grammatically correct and can be used in both formal and informal contexts.