Learn Spanish (Latin America): No hay que cancelar la reserva del hotel. - You must not cancel the hotel reservation.

The phrase hay que expresses an impersonal obligation, meaning 'one must' or 'it is necessary to'. Adding no makes it 'one must not' or 'nobody should'. It applies to people in general rather than a specific person. The English translation uses 'you' in the general sense of 'anyone', but the Spanish sentence intentionally avoids pointing at a specific person.

What is the difference between no hay que and no tienes que?

No tienes que is personal and usually expresses a lack of obligation, meaning 'you don't have to' do something. No hay que, as used in this context, acts as a general rule or strong advice meaning 'one must not' do it at all.

Why isn't the verb cancelar conjugated?

The fixed expression hay que is always followed immediately by an infinitive (a verb in its basic, unconjugated dictionary form ending in -ar, -er, or -ir). You will never conjugate the action verb that comes right after hay que.

Why does the sentence use del hotel instead of de el hotel?

Whenever the preposition de (of/from) is directly followed by the masculine singular article el (the), they must combine to form the contraction del. This is a mandatory spelling and pronunciation rule in Spanish.