I ................... A briefcase once . I don't know if I have still got it .
1- have had 2- had
Should we choose 1 or 2 as an answer to this question ? And why ?
You should choose (2), with the simple past:
- I had a briefcase once. I don't know if I have still got it.
The reason is that "once" (a past-time adverbial) is not compatible with the present perfect. It calls for the simple past here. If you wanted to use the present perfect, you could change "once" to "before," which is one of the few past-time adverbials that work with the present perfect:
- I have had a briefcase before. I don't know if I have still got it.
Remember NOT to use a space before a period or a question mark.