My sentence can be said as: Programming is fun. and it can also be said as: Programming's fun. Both seem to be correct. When should I use one instead of the other?
Does using the word ain’t in a song make it slang, whereas using it in a speech make it colloquial?
Google finds 52,000,000 matches for ain't but non-natives simply can't look up this word. Wiktionary isn't helpful. Is it some kind of 'wildcard' for am/is/are not?