"Après qu'elle a cuisiné le repas, nous avons mangé."
Translation:After she cooked the meal, we ate.
For those wondering why it's après que rather than après here is an explanation.
après + noun / pronoun without an associated conjugated verb
après + verb in the past infinitive (past infinitive indicates an action that occurred before the action of the main verb, but only when the subject of both verbs is the same)
après que + a clause with a conjugated verb (similar constructs include: maintenant que, depuis que, une fois que.)
C’est bon de boire une bière après le ski. - It is good to drink a beer after skiing
Après avoir marché pendant une heure, j‘étais perdu - After walking for an hour I was lost
Après que mon fils m'a donné deslégumes, j'ai cuisiné de la soupe. - After my son gave me vegetables, I cooked soup.
Je dois commencer après qu'il part. - I must start after he leaves.
Je dois commencer après son départ - I must start after his departure.
Il part après son repas - He leaves after his meal
Il part après qu'elle a mangé - he leaves after she has eaten
Il part après avoir mangé. - He leaves after eating
Deux ans après que je suis parti - Two years after I left
Après cela il a marché - After that it worked
Après que je l'ai frappé, il a marché - After I hit it, it worked
Je pensais qu'ils en avaient après toi - I thought they were after you
No. The auxiliary verb is "avoir". This means it can only agree with the direct object if the direct object precedes it. "Mangé" here does not have a direct object.
There is never agreement with the subject if "avoir" is used.
Why is every comment here seemingly from a French language professor. I loathe the comments section, it's rarely helpful and just confuses me more. For Christ's sake it's basic French how about a basic answer to why my answer is wrong.
Ask nicely, provide the answer you gave, and we'll explain why it's wrong using terms you're familiar with. You don't have to put up with grammar terms from a teacher.
If you so loathe the comments sections on Duolingo and find it unhelpful why do you bother to read it and then write disparaging comments regarding those of us who are trying to help fellow learners. Why not expend a little effort yourself (rather than relying on others) and use the internet to answer your question instead of wasting your time insulting and criticising those people who make an effort to help fellow learners on Duolingo's comment section..