Questions & Answers about Я предпочитаю чай.
предпочитаю is:
• present tense
• first person singular (I)
• imperfective aspect
Imperfective verbs describe ongoing, habitual, or repeated actions.
предпочитать follows the first conjugation pattern (even though it ends in –ать). Its present‐tense endings are:
–ю, –ешь, –ет, –ем, –ете, –ют.
That’s why предпочитаю ends in -ю.