Learn Italian: Hai visto tutte le tigri nella gabbia? - Have you seen all the tigers in the cage?

In Italian, when you want to say "all the [noun]" or "all [noun]", you must use tutto/a/i/e followed by the definite article (the "the" word). You can never skip the article like we sometimes do in English. So it must be tutte (all) + le (the) + tigri (tigers).

Wait, why is it le tigri? Doesn't the -i ending mean it's masculine plural?

Not always! The singular word for tiger is la tigre, which is a feminine noun that ends in -e. Nouns ending in -e in the singular always change to -i in the plural, regardless of their gender. So la tigre becomes le tigri, and the word for "all" must match this feminine plural form to become tutte.

If the tigers are feminine plural, why is the verb visto instead of viste?

Because the helping verb here is avere (hai). In this past tense, the past participle (visto) usually only changes its ending to match gender and number if the helping verb is essere. With avere, it stays in the default -o form (unless you use a direct object pronoun right before the verb, which isn't happening here).

How did "in the cage" become nella gabbia?