As I know that slang is an uncountable noun. But can we add an ' s ' to mean different types of slang like what we do on ' foods ' and ' peoples ' ?
eg. I am running a company dealing in wine and foods.
eg. Peoples from different nations come to attend the world conference.
Thanks
Yes- Cockney rhyming slang is an identifiablt and localised slang. It is different from others, so the plural would be possible if we were thinking about local, etc, variations.
I'd say there are many different slangs in the UK. You could avoid the issue with something like 'kinds of slang', but the plural doesn't worry me at all. It's that BE singular\plural laxity again.