sealy

[light coral]

Please be patient

Our volunteers look into many questions every day; sometimes it takes them a little while to answer.

Pro tip: you can rename the thread title with `.tr <thread name>`

Make it descriptive, including relevant context, but also to the point. This way you improve your chances of getting a more relevant and specific answer.

[rare wing]

it's not

[cedar badge]

Is it? I would just say « Il y a une trentaine de cafés. »
Regarding why it’s « de », it’s an expression of quantity and so you don’t need the definite article since you’re talking about a non-specific set of items.