Formal:
* मुझे तुमसे बहुत प्यार है, भाई। (mujhe tumse bahut pyaar hai, bhai.) - This is the most formal way to say it, using the pronoun "tum" for respectful address.
Informal:
* मैं तुम्हें बहुत प्यार करता हूँ, भाई। (main tumhen bahut pyaar karta hoon, bhai.) - This is a more casual and affectionate way to say it, using the pronoun "tumhen" for informal address.
* मैं तुम्हें बहुत प्यार करती हूँ, भाई। (main tumhen bahut pyaar karti hoon, bhai.) - This is the feminine version of the above, using "karti hoon" instead of "karta hoon".
* मैं तुझे बहुत प्यार करता हूँ, भाई। (main tujhe bahut pyaar karta hoon, bhai.) - This is the most informal version, using the pronoun "tujhe".
You can also use other terms of endearment instead of "bhai" depending on your relationship:
* भाईजान (bhaijan) - Brother (used mostly in Northern India)
* भाई साहब (bhai sahab) - Brother (formal and respectful)
Remember to adjust the pronoun and verb conjugation based on your gender and the gender of the person you are speaking to.