我唔明白刑事法律: 1) 守行為同援刑, 有乜分別? 好似大家都係要去報到, 同要有人擔保, 聽落, 援刑係比守行為重, 重在那? 2) 18個援刑, 及坐牢2個月, 係咪即係一定要坐左2個月牢先出倒來? 再18個月? 咁都出左來, 18個月前後有乜分別?

1. The major difference is suspended sentence is a criminal conviction and binding over is not a criminal conviction.

In short - binding over is more like a warning. It provides a chance for people who committed minor offense a new chance. On the other hand, suspended sentence is a condition. After the court imposes a punishment, the court suspends it so that you will not end up losing your freedom.

2. No. Your 2-month imprisonment will be suspended for 18 months. If you have met the condition set by the court after 18 months, that 2-month imprisonment is gone.

See here for detail:

http://www.hkclic.org/tc/topics/policeAndCrime/criminal_liability_and_penalties/q2.shtml