Learn Portuguese (Portugal): Eles querem reservar uma mesa no restaurante. - They want to reserve a table at the restaurant.

When using a verb like querer (to want) followed by another action, the second verb stays in its full, unchanged dictionary form called the infinitive. Here, that is reservar. Unlike in English, you do not need a connecting word like "to" between the two verbs.

Is querem a regular verb?

No, querer is an irregular verb. For the pronoun eles (they), it becomes querem. Because it is irregular, it does not perfectly follow the standard patterns of other verbs ending in -er, so this specific form just needs to be memorized.

Why is the word no used before restaurante?

No is a mandatory combination of the preposition em (at/in) and the masculine word for "the", which is o. Because restaurante is a masculine noun, "at the restaurant" translates to em plus o, which merges into no.

How do I correctly pronounce the ending of querem?

The -em ending does not sound like the English word "them". It is a nasal sound. It sounds very similar to the "aing" in the English word "saying", but you stop before making any hard "g" sound at the end.