On va ou on irons?

Question

Question today was "Un jour, on _____ sur Mars."  In a previous   test, "On a ______ opinion."  The previous answer was "On a notre opinion," but today's test was said to be "On ira sur Mars."  How is one to know if the "on" refers to a singular person (on ira) or to several individuals (On a notre opinion)?  It's a bit confusing.  Please clarify.  Thanks.

Accepted Answer

Hi Carol,
I think your question is about the pronoun 'on' and what it represents.
It never refers to a single person.
In the case of the example with going to Mars, it replaces, we,
one day, we, (humans from Earth) will go to Mars
and most often it replaces nous
Dimanche, on ira à la mer = We'll go to the sea on Sunday
Sometimes it replaces the universal you, people or, one -
On a notre opinion = People have their own opinion
Take a look again at the following Kwiziq lesson with lots more examples -
https://french.kwiziq.com/revision/grammar/on-can-mean-we-one-and-people

Answer

It can be difficult - it relies entirely on context. Unless you know the context you really can't be sure when just presented with a single phrase. Of course, there are usually expressions that just have to be learnt to be known. However, in the context of your question, it doesn't matter as "on" always conjugates as the singular 3rd person so the verb form does not change. Hence «on ira» in the lesson here, and «on a» in the other lesson. The impact is on the possessive used - son/sa/ses or notre/nos (with possessive agreement as usual with the possession). Back to 'On a ... opinion' if this was a statement about a defined group of people, of which you were one, it would be «on a notre opinion» (we all have our opinion), but as a general statement it is 'on a son opinion' (everyone/all have an (their) opinion).

Not sure if the link will work, but if not search QandA for possessives with 'on' and there is some good detail in a previous answer.

https://french.kwiziq.com/search?s=on+with+possessives