“Eiti” means to go and is one of the best friends of prefixes. Normally “paeiti” means to walk short distance or to be able to walk.

-Paeinam biškį, čia smirdi.
-Let’s move a bit, it stinks in here.

-Man labai skauda koją, negaliu paeiti.
-My leg hurts a lot, I cannot walk.

In slang we like to use negative form of it, “nepaeiti”. Then it means “not to succeed”, “not to make it”. In this case we use only third person form and mostly past or future tenses. Sometimes you can hear that people add the word “korta” (card) to it. I guess this saying comes from playing cards.

-Gal turi Akvilės numerį?
-Jo, bet tau vis tiek nepaeis.

-Do you have Akvilė’s number?
-Yeah but no chance you would make it.

Let’s say you play a card and lose. Then you say:
-Ech, nepaėjo.
-Eh, it didn’t work.