The noun 'work' and its plural

Hello,

I was once told by a friend that the noun WORK has no plural, but i kept on seeing them and finally checked it out for myself and it appeared that WORKS can have different meanings for example, WORKS=PHYSICS.But what about simple sentences as follows:

They have to finish their work
They have to finish their works

which is the correct one?

Nina

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As with many nouns, there are countable and uncountable uses for work. Here, the non-count is appropriate: They have to finish their work. We use uncountable work for the job we do or the labour we put in. Below, on the other hand, are several uses for the plural form, gleaned from a concordance engine:

ned conspicuous through his later works- a genius for describing military a
iciency engineers from the Stanley Works. Already this study has suggested
n a Nassau hotel, an Ohio pottery works, and a detergent for window-washing
e Rebels surrendered within their works and a thousand more were captured
t to be saved by any form of good works, and just now receive Jesus as my
at Flushing Meadow Park is in the works, and once the lease is signed the
between good and enduring literary works and the ephemeral mass culture pro
lf produced a number of brilliant works, and these form a transition from
ility of the Department of Public Works and was financed on a rotary fund
and humorous. Of course, these works are not comparable, even though th

And welcome to English-test, Nina.
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Oh, thank you! That was fast.I didn’t know there were countable and uncountable uses for work before, and thank you for the examples.