Because French is a romantic language and English is a germanic language, direct translations like that can be difficult. There are many different ways to say "When to go" depending on the context of the sentence and the amount of formality to be used. Also, "When to go" isn't exactly how the French would word it.
For example...
When I must go: Quand je dois aller
When you must go (formal/informal): Quand vous devez/tu dois aller
When he/she/one must go: Quand il/elle/on doit aller
When we must go: Quand nous devons aller
When they must go: Quand ils/elles doivent aller
Or to word it differently: "When it is required/necessary to go": Quand il faut aller
(or the subjunctive which translates to "When it is required/neccessary that one goes": Quand il faut qu'on aille
But anyways, words are easy to translate, sentences or parts of sentences like "When to go" can be a little trickier if you don't provide a sentence for it to fit into. The ony thing I can think of is "I don't know when to go there." which would be "Je ne sais pas quand y aller." but most frequently it would be used with aller in one of its conjugated forms like "When I go" which is "Quand je vais."
aller is how you say go in french. x
To say "I knew" in French, you would say "Je savais."
To say, "Will you go out with me one day?" in French you say: Sortirez-vous avec moi un jour ?
to go to is 'aller à ... (place name)' in French.
Partir
The translation for "go down" in French is "descendre".
jus go on french translation and find out
The french wouldn't say "the movies" to mean a movie theater, they'd say "I go to the cinema." Je vais au cinéma
"To go there"- "Pour y aller"
Gardeno
Dur
Je vais