I’m VERY confused with this Spanish sentence and it seems almost impossible to complete. Anyone know how to find the correct verb conjugation for this one? The hint is shown in parentheses as “Tú: Perderlas”.

Directions: Complete the sentences with the perfect present of the verbs in parentheses to describe what Ramon and Teresa have done (or not) until now during their journey through South America.

My Problem: ¡Ramón! ¿No encuentras las tarjetas de embarque? ¿(Tú: Perderlas)?