赶不上

趕不上
gǎnbùshàng
  1. can't keep up with
  2. can't catch up with
  3. cannot overtake

CEDICT

Entry Composition

1 赶 gǎn
  1. to overtake; to catch up with
  2. to hurry; to rush
  3. to try to catch (the bus etc)
  4. to drive (cattle etc) forward; to drive (sb) away
  5. to avail oneself of (an opportunity)
  6. until; by (a certain time)
2 不 bù
  1. no; not so
  2. (bound form) not; un-
3 上 shàng
  1. (bound form) up; upper; above; previous
  2. first (of multiple parts)
  3. to climb; to get onto; to go up
  4. to attend (class or university)
  5. (directional complement) up
  6. (noun suffix) on; above