There does not exist in French a true equivalent for the use of the preposition as a summing-up for a complement that has been used in the preceding phrase, complement that is apparently often an infinitival clause but not always. Instead, in French a pronoun is used : le, yça, çay, quoien. (I have no certitude that there aren't more than four, though.)
- They are going to tell the mayor to do something about it. Are they really going to?
Ils vont demander au maire de faire quelque chose. Vont-ils vraiment le faire ?
- -- We'll have to go faster. -- Are you allowed to?
-- Nous allons devoir aller plus vite. -- Vous y êtes autorisé ?
- -- All the striking workers will gather in this place tomorrow. -- Do they have to?
-- Tous les travailleurs en grève se réuniront à cet endroit demain. -- Ça leur est nécessaire ?
- -- There is no more room but if there is too muchThe teachers have the insects do not behave inpossibility to put pressure on the same way, so they are kept in conditions of close coexistence in order to ensure they have certain reactionsadministration. -- That's what the crowding boils downDo they intend to then, force the insects to do what you want ?
-- Il n'y a pas de place mais s'il y a trop de place les insectes ne se comportent pas deLes enseignants ont la même façon, en raison de cela il sont maintenus dans des conditionspossibilité de proche coexistence pour assurer qu'il aient certaines réactionsfaire pression sur l'administration. -- C'est àIls quoien revient leur grande proximité les uns des autres, alors, les forcer à faire ce que vous voulezont l'intention ?
The given example is translated as follows.
- Will you do the thing?
- I'm hoping to.
Ferez-vous cela/ça ? or le ferez-vous? (formal) _ Vous ferez ça/cela ? (colloquial)
Je l'espère.
Instead of "Je l'espère." the speaker may however say "J'espère ça.(!)" and adopt any one tonestone of voice in a variety of them from self-assured to cocky or angry, so as to connote his/her state of mindmind; of course, that can be associated with only a particularised context and not the most general one.