Learn Italian: La ragazza sta attenta alla lezione. - The girl pays attention to the lesson.

In Italian, the expression for paying attention or being careful uses the verb stare instead of essere (to be). It literally translates to staying attentive. So, sta attenta is the standard way to say pays attention.

Why does the word attenta end in an -a?

Attento is an adjective, so its ending must match the noun it describes. Since it describes la ragazza (a feminine singular noun), the ending changes to -a. If a boy were paying attention, it would be il ragazzo sta attento.

Where does the word alla come from?

Alla is a combined word meaning to the. It is made by gluing together the preposition a (to) and the feminine singular article la (the), which is required by the feminine noun lezione.

The word lezione ends in -e. How do we know it is feminine?

Nouns ending in -e can be masculine or feminine, which you usually just have to memorize. However, there is a very helpful rule here: almost all Italian nouns ending in -zione are feminine! That is why it takes the feminine article la.