From the sharedle- stem ofvan(“to be”) andlesz(“to become; will be”) +-ne(personal suffix).
lenne
Since the synonymousvolna comes from the stem that expresses the past tense, andlenne is similarly connected to the future (cf.volt andlesz),volna suits impossible scenarios, while it might not be advisable in requests. Instead,lenne enjoys more widespread currency. At the same time,volna is part of the past conditional, following the past form of the given verb.