What is the difference in practice between verb, verb-short, short and long form?

Hi,
Where can I find the explanation of differencies between verb, verb-short, short and long form?
thanks,
Mihai

This is an old discussion that has not been active in a long time. Instead of commenting here, you should start a new discussion. If you think the content of this discussion is still relevant, you can link to it from your new discussion.