Questions & Answers about Wir empfangen heute Gäste.
Because the subject is wir (we), and the present-tense form for wir is the infinitive form without zu:
- ich empfange
- du empfängst
- er/sie/es empfängt
- wir empfangen
- ihr empfangt
- sie/Sie empfangen
So Wir empfangen is the correct present-tense form for we receive / we are receiving.
Gäste is in the accusative case because it is the direct object of empfangen.
In this sentence:
- Wir = subject, nominative
- empfangen = verb
- Gäste = direct object, accusative
The reason it does not visibly change is that many plural nouns in German look the same in the nominative and accusative:
- nominative plural: die Gäste
- accusative plural: die Gäste
So the case is accusative, even though the noun form itself stays the same.