(がんば)って

がんばって
expression
good luck, do your best
1. good luck, do your best, hang in there
An expression of encouragement. It comes from the verb 頑張(がんば)る (to persevere, to do one's best). Used to cheer someone on.
試験(しけん)頑張(がんば)って!
Good luck on your exam!
頑張(がんば)ってください
Please do your best.
Polite form
もう(すこ)だから頑張(がんば)って!
Just a little more, hang in there!
Good luck in tomorrow's game. I'm cheering for you.
He was tired from work, but he persevered and finished it to the end.
Using 頑張る verb form

頑張(がんば)って is the te-form of 頑張(がんば)る used as an expression of encouragement. It's very commonly used before tests, competitions, or any challenging situation. The polite form is 頑張(がんば)ってください. Note that in Western culture 'good luck' implies chance, but 頑張(がんば)って implies effort and perseverance.