Almost taking a year to learn to swim (6)
I believe the answer is:
nearly
'almost' is the definition.
(I know that almost can be written as nearly)
'a year to learn to swim' is the wordplay.
'a year' becomes 'y' ().
'to' is a charade indicator (letters next to each other) (I've seen this in other clues).
'to swim' is an anagram indicator.
'learn' anagrammed gives 'nearl'.
'y' after 'nearl' is 'NEARLY'.
'taking' acts as a link.
(Other definitions for nearly that I've seen before include "Noon at eleven fifty nine am" , "Almost, well-nigh" , "More or less" , "pretty much" , "Almost, not quite" .)