Learn Spanish (Latin America): Ellos no pueden llamar hoy.

When two verbs work together to form a single idea, only the first one (pueden) changes to match the subject (ellos). The second verb (llamar) stays in its infinitive or base form. This pattern (poder + infinitive) is exactly how you express ability or say someone "can do" something in Spanish.

Why is the verb spelled pueden instead of "poden"?

The verb poder (to be able to) is a stem-changing verb. This means the o in the stem changes to ue in most present tense forms. For ellos (they), it becomes pueden.

Where does the word no go when there are two verbs like this?

In Spanish, the negative word no always goes directly in front of the conjugated verb. Even though there are two verbs in the sentence (pueden and llamar), the no must go right before pueden.

Could I leave out the word ellos?

Yes! If it is already clear from the context that you are talking about a group of men or a mixed group, you can drop ellos and simply say No pueden llamar hoy. The ending of pueden already narrows the subject down to "they" or "you all".