Learn Portuguese (Portugal): O professor está no supermercado.

The verb está comes from estar (to be). Even though it ends in '-ar', it is an irregular verb, meaning it does not follow the exact same pattern as the regular '-ar' verbs you are studying. However, its 'he/she/it' ending here is -a, which matches the regular pattern, it just gets an extra accent mark to become está.

Why does the sentence use está instead of é for the word "is"?

Portuguese has two verbs for "to be": ser and estar. We use estar (which gives us está for "he is") to talk about physical locations. Since being at the supermarket is a temporary location for the teacher, está is the correct choice.

Where does the word no come from in this sentence?

The word no translates to "in the" or "at the". In Portuguese, when the preposition em (in/at/on) is followed by the masculine word for "the" (o), they must combine into the contraction no. We use no here because supermercado is a masculine noun.

Can professor mean a normal school teacher, or just a university professor?