Snakeair's advice is basically correct. If the forum is not in English then you must ensure that you submit to the correct language section of DMOZ.
The slight inaccuracy of that answer is that no one can predict how long it will take for a review. It could be much more than a year before the site is reviewed for a possible listing. DMOZ relies on someone who can edit in that section to volunteer to work there and to use the suggestions as their resource and no one can predict when that will be.
Two other comments
1. The age of a site is not normally a problem in DMOZ, but it can be with forums and blogs, DMOZ likes to see that the forum is being used and that over a period of time.
2. Do not re-suggest a site, that puts it to the bottom of the pile and with enough re-suggestions can be seen as spam and we all know what we do with spam!
I am a DMOZ editor but my opinions are my own and do not represent DMOZ or anyone else.