(1) According to the meaning of the question, if L is regarded as a whole, there is a P2^2 queuing method, and the other four people have a P4^4 queuing method.

∴p2^2×p4^4=2×4×3×2× 1=48；

(2) The total number of five people queuing for free: p55 = 5× 4× 3× 2×1=120,

∴ 120-48=72;

Answer: If two people must be adjacent, there are 48 different ways to queue.

If two people can't be adjacent, there are 72 different ways to queue.