« Ça » vs. « Il »

Question

Salut tout le monde,

I'm having a problem determining when it's best to use « ça » or « il » in contexts such as the following:

Ils ont mangé tout le chocolat. ＿＿ leur fera mal au ventre.

Since they ate it (i.e., the chocolate), would you be able to use either « ça » or « il »?

Only « ça »?

Only « il »?

If you can only use « ça », how does the statement with the blank space above differ from the use of « elle » in the following context:

Voici sa maison. Elle (la maison) est très grande.

I'm aware that this topic has been discussed plenty of times, but I wasn't able to find a clear answer to this type of question.

Merci beaucoup.

Answer 1

I would say that the use of "ça" or "il"/"elle" depends on what the subject of the sentence represents:

• "ça" if it's an action
• "il" or "elle" if it's a person or an object

In your first example, it is not the chocolate that will cause stomach ache: it is the action of eating it all. Therefore, "ça" is used.

In your second example, since the house is the subject of the sentence and a feminine word, "elle" is used.

If you say:

Ils ont repeint la maison. Ça lui redonne un aspect neuf.

Here, it is the action of repainting the house that gives it a new look, so "ça" is used.

But now, if you say:

Ils ont repeint la maison. Elle a l'air neuve.

Here, even if there is the action of repainting the house, it is the house that looks new, so "elle" is used.