Breakdown of Il faut garder le secret pour soi.
pour
for
il
it (impersonal subject)
falloir
to be necessary / must (impersonal)
garder
to keep
Questions & Answers about Il faut garder le secret pour soi.
Why do we use soi at the end instead of lui or elle?
Would it mean something different if I said Il faut garder le secret pour lui?
Yes! Because Il faut doesn't refer to a specific "he", using pour lui just means "for him" (a separate person). The sentence would mean "One must keep the secret for him." To mean "keep the secret to himself" referring to a specific man, you would need to change the subject: Il doit garder le secret pour lui.
Why isn't the verb garder conjugated here?
The impersonal expression Il faut is followed directly by an infinitive verb (like garder) when stating a general necessity or rule. You don't conjugate it because the sentence literally functions like "It is necessary to keep" or "One must keep."