说不定 shuōbudìng
说不定（shuōbudìng）means “说不定: maybe, perhaps; who knows (it might well be that…)”. 说不定 expresses a guess: 'maybe, perhaps, it could well be that…'. Formation: 说不定 + 小句（也许、可能）
说不定: maybe, perhaps; who knows (it might well be that…)
HSK4Formation
说不定 + 小句（也许、可能）
Explanation
说不定 expresses a guess: 'maybe, perhaps, it could well be that…'. Literally 'can't say for sure', it leans slightly toward the possibility being true, often with a hopeful or speculative tone. It can start the sentence or come after the subject, and often pairs with 会 or 能.
Examples
Note
Slightly more hopeful/likely than 也许. Can begin the sentence.
FAQ
说不定 — what does it mean and how is it used?
说不定: maybe, perhaps; who knows (it might well be that…). 说不定 expresses a guess: 'maybe, perhaps, it could well be that…'. Literally 'can't say for sure', it leans slightly toward the possibility being true, often with a hopeful or speculative tone. It can start the sentence or come after the subject, and often pairs with 会 or 能.
说不定 — how do you form it?
说不定 + 小句（也许、可能）
说不定 — any usage notes?
Slightly more hopeful/likely than 也许. Can begin the sentence.