Well, a capital letter is needed at the beginning of ever sentence. If that's what you meant .
Mostly when youre thinking of it, it's present tense while also being future tense as well, could, meaning in the present. For example, "I could do that". More than likely your sentence is in the present
Bon nuit, mon cherie would translate as - Good night, my darling.
It is a French expression you use when you want to tell someone to sleep tight, basically.
both/and, either/or, neither/nor, not/but, not only/but also
