"You have to be big."
Translation:Vous devez être grands.
"on" means "we", but you have to translate "you", then you have to use "tu" or "vous"
Hi, my answer was "vous devez être grand", grand not in the plural. My interpretation was that I was talking to someone in a formal manner and not with more than one person. So my question is, is it wrong to write grand in the singular or I always have to write it in the plural when I use vous even if in the context it's just one person?
"vous" is either polite singular or simply plural (2 individuals or more), and "vous" can be masculine or feminine.
Consequently, if you use "vous", adjective "grand" can take all variants: grand, grande, grands, grandes.
The correct verb form is in the subjunctive : "il faut que tu SOIS grand" and plural/polite : "il faut que vous SOYEZ grand/s/es)
If the English sentence contains "we", you can translate to 1) "nous" or 2) "on"
If the English sentence contains "you" and has a general meaning (like: you should brush your teeth at least twice a day), you can translate to 1) "vous", 2) "nous" or 3) "on"
If the English sentence contains "you" with no 'advice' value, you can translate to 1) vous or 2) "tu".
This exercise is called "Verbes à l'infinitif" that means you have to keep the second verb (sois) in the infinitive form. The infinitive of "sois" is "être" that's why the correct sentence is "Il faut être grand".
It depends whom you are addressing, since "vous" can be singular, masculine or feminine, or plural, masculine or feminine:
- Vous devez être grand / grande / grands / grandes
In any event, please note that "grand(e)(s)" is the translation for "tall" (height) and that "big" better translates to "fort(e)(s)" or "costaud(e)(s)" which for people mean "strong/sturdy".