Forming inverted questions with nouns in Le Passé Composé (conversational past)

Inverted questions are more elegant. Depending on the actual situation, it might sound approriate or over-the-top. It isn't a good habit in general. You need to develop a feel for when they fit and when not. 

-- Chris (not a anative speaker). 

It is not the comma that is the problem; rather, you are missing an accent aigu on "les invités" and you must have a hyphen when writing a question with inversion (sont-ils ).

Bonjour Helen, In short, no. Here is the rule, from the lesson, for forming inverted questions: Note that all those sentences start with a noun (les enfants / Anne / le petit garçon / Thomas et toi), and not by il, elle, ils, elles, vous or nous. In those cases, when turning the sentence into a question, you still need to include il, elle, nous, vous, ils or elles (matching with the noun) after the verb "avoir/être", with a hyphen. Example: if the noun is ''Anne'', you will use elle (feminine singular). If it's ''Le petit garçon'', you will use il (masculine singular). The inverted form is constructed to have the verb followed by a pronoun when a named person is part of the question. Below is to a link on another site that gives a little bit different explanation: http://www.laits.utexas.edu/tex/gr/int3.html J'espère que ma réponse vous aiderait. Bonne chance et bonne continuation dans vos études en français, la langue de Molière et qui a été utilisé par le monde français depuis l’époque d’Hugues Capet

Hi Helen,

You can say: "Est-ce que Anne est allée au marché?

Hope this helps!