"Byddwn i'n garddio."
Translation:I would be gardening.
Thanks to both for your comments - I reacted a bit hastily as I should have remembered that 'bydda i' is the future in the first person. It is becoming clearer (slowly)!
This is the conditional tense 'would' and apologies that it looks so similar to the future tense.
There are two variations in the conditional:-
eg I would garden
'Baswn i'n garddio' - which is clearly different to the future
Byddwn i'n garddio' - which is very similar
I think we're going to have to review this section to lessen the confusion.