The prefix pa, when used with verbs of movement, means that the movement was done a little. It also gives some of these verbs a figurative meaning.

paeiti - to go/walk a little; to be able to walk
pabėgti - to run a little; to be able to run; to escape
pavažiuoti - to go (by a transport) a little; to be able to drive
paskristi - to fly a little; to be able to fly
pajoti - to ride a little; to be able to ride
paplaukti - to swim a little; to be able to swim

Aš paeinu nuo mokyklos. I walk a little away from school.
Aš nepaeinu. I can hardly walk.
Aš negaliu paeiti. I can't walk.
Aš negaliu eiti. I can't go.
Aš negaliu eiti į koncertą. I can't go to the concert.
Dėstytojas pabėga nuo studentų. The lecturer escapes from the students.
Laivas paplaukia ir paskęsta. The ship swims a little and sinks.
Arklys nepajoja. The horse can hardly ride.
Paukštis nepaskrenda. The bird can hardly fly.
Lėktuvas truputį paskrenda, bet nukrinta. The plane flies a little, but falls down.