Learn Portuguese (Portugal): O gato é de Lisboa?

In Portuguese, yes/no questions use the exact same word order as regular statements. You do not swap the subject and verb like we do in English. To show it is a question, you simply raise the pitch of your voice at the end of the sentence.

Why do we use é here instead of está?

We use é, which comes from the verb ser (to be), because where someone or something is from is considered a permanent trait. The other verb for to be, estar, is used for temporary locations, like if the cat is just visiting Lisboa for the weekend!

The lesson teaches de onde (from where). Why do we only use de here?

You use de onde when the location is the missing information you want to find out, like in De onde é o gato? (Where is the cat from?). In this sentence, we are just asking a yes/no question to confirm a specific place, so we only need de (from) before Lisboa.

Why is it just de Lisboa and not combined with an article like da Lisboa?

In Portuguese, most cities (including Lisboa) do not take a definite article. Because there is no hidden article to combine with the preposition de, it stays exactly as de Lisboa.