Questions & Answers about Esto es un regalo para ti.
Why is it esto and not este or esta?
Why use para instead of por in this sentence?
Para is used here because it indicates a destination or recipient. Whenever you are giving a physical item to someone, that person is the destination of the object, so you always use para.
Why is the word for "you" ti here instead of tú?
After a preposition like para, de, or a, you must use a prepositional pronoun. For the informal "you", this form is ti. You will always say para ti (for you) instead of para tú.