What is the English translation of the Latin word 'amo te'?

Not easily.

The Words ti and bi don't exist in Latin. "Ti bi" could be, and probably is, tibi, which means "to you" or "for you" (singular).

Qua could be any number of things depending on context, including "where", "how", "as far as", "by which".

Amo is "I love".

Together they mean something like "to you as far as I love", or "to you how I love". A better translation would require more knowledge of the context.

Is it possible that the text is actually Tibi quam amo? That would be easy to translate: "To you whom I love" (spoken to a female; otherwise quam would be quem).