Ils se sont téléphoné?
Why in this case does the past participle not agree with the subject? In other words why is it incorrect to write: ils se sont téléphonés?
In general, specific questions about a specific sentence already has a thread, accessible from the question itself. LICA98's comment brought you to that post, but if you follow the link where it told you you were right or wrong, you'll go there directly.
well what if it wasn't a question about a sentence but you just saw it elsewhere?
Thank you. That sounds very useful but I see no link in the “grading window”. The only options are “My answer was correct”, “There is another problem”, or “Continue”. Can you illustrate the link you are talking about, please? I am using the iOS app. Thanks.