Да нет, наверное.

3년 전

Да нет, наверное. Have you already met this phrase? 
Да= yes
Нет=no
Наверное=probably
Да нет,наверное = probably not ‍🤯
And here's why
"Да" is often used as an intensifying particle and always take place at the beginning of the sentence. In this case the phrase "нет, наверное" sounds more expressive after "да".
More expressions with the particle "да":
•Да что с тобой такое?! (What is wrong with you?!) 
•Ну, да что там говорить.. (Well, what can I say) 
•Да что там происходит?! (What is going on out there?!)
•Да неужели! (oh, really/finally) 
•Да не бойся! Это не страшно! (Don't be afraid! It's not scary)...говорили они перед прыжком с парашютом 😰😂 
It's possible to omit "да" in all these phrases 🤗