I`ve heard people using it differently: someone says 2 sec, while others 2 secs.
2 secs sounds like sex to me.
Which one is correct?
Hi Take_it_easy,
I presume you are referring to time. Thus, ‘2 seconds’ would be correct.
The only time I would use ‘sec’ in informal spoken English would be in an expression such as ‘Just a sec’ or ‘Wait a sec’. In other words, I would use neither ‘2 sec’ nor ‘2 secs’; I’d only talk about a single second. I have also heard lots of others use ‘a sec’ this way.
So, if you’ve heard one person say ‘2 sec’ and another say ‘2 secs’, both sound like personal styles/choices to me rather than something that is commonly used. However, if I were forced to choose one or the other, I would choose ‘2 secs’.
[color=darkblue]______________________________________________________________________________________
[size=75]“When you are courting a nice girl, an hour seems like a second. When you sit on a red-hot cinder, a second seems like an hour. That’s relativity.” ~ Albert Einstein [/size]
Hello Take_It_Easy,
I’m wondering if what you’re talking about is the abbreviation of the word second.
I think that [size=200]sec.[/size] is used in the sense of either “second” or “seconds”.
As far as I’m concerned, in speech the standard rule applies:
Just a sec. (singular)
Just 2 secs. (plural)
Just a couple of secs.(plural)
etc.
In writing, where used as a time abbreviation, I’ve known both to be accepted:
5hr 22sec.
or
5hrs 22secs.
Thanks for the answer from all of you. Yes, I referred to the time.
Sometimes, I still cant get used to that in english, there is always the plural version of the word used instead of singular, whereas in my language, its not needed to use the pluralone if there`s any number behind the noun, for instance two sec instead of secs or two girl (instead of girls) my language is lazy 
It doesnt belong to the subject, just thought Id share it with you as an interesting fact.
Indeed, I don`t hear too often using 2 secs, whereas 1 sec is rather in the usage.
Thanks again.
If you’re dealing with technical literature, the abbreviation “sec.” is correct for both singular and plural.