Fòram na Gàidhlig

Forgive me if this question has been answered somewhere before. Now, I was studying a Gaelic dialogue when I came across a part where two people were discussing their plans for the night, and this sentence came up:
'S toil leam a bhith a' dannsadh, ge tà.

Now, the part that confuses me is the "a bhith a' dannsadh" bit. Why is it necessary to say that "I like to be (at) dancing" as opposed to simply "'S toil leam dannsadh" ? Is it something to do with the type of noun that dannsadh is? Am I reading it wrong? The phrase itself is simply translated as "I like dancing, though." as opposed to the more literal "I like to be dancing." So that is why I am confused. Help? Tapadh leibh!

Is toil leam a bhith a' dannsadh - I like to be dancing.
Is toil leam dannsadh - I like dancing.

You sometimes need to take translations with a grain of salt.

Technically, 'S toil leam dannsa could mean I like the art-form 'dance' or I like watching dancing.

If you want to emphasise that you actually like doing it, the 'a bhith a' dannsa' gets that across clearly. You're imagining yourself doing it as you speak, more or less.

Same applies to all that sort of verb, with activites like swimming, running etc.

...not forgetting "'S toil leam a bhith a bhith a' faicinn", or "I like BBC-ing"...

"I like dancing" could mean "I like to dance", or "I like watching Dancing with the Stars".

'S toil dannsa is like "I like dancing", and ambiguous.
'S toil leam a bhith a' dannsa is roughly equivalent to "I like to dance", and is unambiguous.