Learn Italian: Faccio colazione alle otto. - I have breakfast at eight.

In English we say "have breakfast", but Italians literally "do" or "make" breakfast. The standard phrase is fare colazione, and faccio is the "I" form of the verb fare (to do/make).

Why is there no word for "the" before colazione?

It is a set phrase. Just like in English where we say "have breakfast" rather than "have the breakfast", Italian uses fare colazione without any article.

Why do we use alle instead of just a (at) before the time?

Alle is a combination of a (at) and le (the plural "the"). When telling time in Italian, you always include "the". Because the hidden word for hours (le ore) is feminine and plural, a plus le combines into alle.

How do we know otto means "eight o'clock" and not just the number eight?

When talking about time, the word for "hours" is understood but left out. Whenever you see a number immediately following alle, it automatically means you are talking about the time of day.