Hi Niwantha, As you are referring to the single concept of paid absence from duty, "leave" should be an uncountable noun. For example, we could say that you are taking three days of leave or you applied for a three-day leave, but not three days of leaves. You are entitled to 14 days of annual leave, but not 14 annual leaves. So, you can count the number of days of "leave", but you cannot pluralise it. "leaves" is used as either a verb (v) or a plural noun to refer to plant parts that carry out photosynthesis. Examples: He always leaves (v) on the dot. / The tree sheds its leaves (n-plural) during winter. Hope this helps. Lance

"Leave" in this sense is an uncountable noun. The 'proof' that it's uncountable is that you can say, for example, "How much sick leave do you have left?". "Leave" is a kind of commodity (like patience or goodwill), so it cannot have a plural form. You cannot count "leave", but you can count days, so, as the other members have said, you could say "sick days" or "days of sick leave".

I have 3 days of sick leave left this year.

I don’t think leave has a plural form in this case. I would say “I have three sick days left this year.”