問問英文tense 的疑難

我係2010年12月5日偷左隻錶，不過我係2010年12月6日將隻錶俾返間錶行，宜家坐緊牢。

I stole a watch on 5th December 2010, but returned it to the store the day after. Now, I am in the prison.
(we use simple past tense to state what happened in the past)

"steal" is a verb to describe an action which should complete momentarily. We can use present perfect tense to state our experience in the past or state the action has "just" completed.

Example:
1. I have stolen a watch before.
2. I have just stolen a watch.
3. I have already stolen a watch.

But, it doesn't make sense to say, "I have stolen a watch for three years."

2015-03-16 03:25:15 補充：
Correction: (no article needed before prison)
Now, I am in prison.

The present perfect shows present results of past actions.Note that the words "for" and "since" are used,whether imprisoned or not.
eg"-I have stolen a watch Dec5 for many years.
I have returned the watch for the next day,Dec6, since conscience conscientious.