19.3 Qui / Que and the est-ce que forms

Now we have two little specialties. We already know that the est-ce que can be used for any type of question. However, when used with questions that ask with qui / que, there is a difference between asking for a nominative/subject and asking for an accusative/direct object. This differentiation is to be seen in two different forms:

1) If qui asks for a nominative/subject that is a person the sequence of words in the clause is unchanged and     the question is solely formed by pronunciation.
    If qui asks for nominative/subject that is a thing or for an accusative/direct object an inversion is used.
  2) The construction est-ce que changes to est-ce qui if the question is for the nominative/subject of the     clause.

Have a look at this overview:.

What? Function? Example  
person qui nominative/
Qui a fait ça?
est-ce qui a fait ça?
Who has done it?
  person qui accusative/
direct object
Qui vois-tu?
est-ce que tu vois?
Whom do you see?
  thing que nominative/
Que se cache-t-il derrière ce slogan?*
est-ce qui se cache derrière ce slogan?
What is hidden behind the this slogan?
  thing que accusative/
direct object
Que vois-tu?
est-ce que tu vois?
What do you see?

* Actually, questions asking for the nominative/subject of a clause, which is a non-living thing are usually formed with the est-ce que - form. Only with certain verbs (cacher, se passer, falloir) the construction with que plus inversion can be used.

Que faut-il faire maintenant? <=> What is to be done now?
Que se passe-t-il? <=> What happened?

contact privacy statement imprint