"I am your sister."
Translation:मैं तुम्हारी बहन हूँ।
आप (aap) is You.respect (for elders, strangers, etc.) तुम (tum) is You.familiar (for friends, close colleagues, people you are closer with) तू (tuu) is You.informal (for small children, close romantic partners, pets, etc.) aapki(/a), tumhari(/a), and teri(/a) are the possessive forms of each of these (i.e. "your")