A lot of new supermarkets are being built in Warsaw now.
Why not: is being built - if I think about: A lot ?
please tell me, in which cases we write:
A lot of new supermarkets is being built
and
A lot of new supermarkets are being built
thanks.
The verb relates to ‘supermarkets’, not ‘a lot’.
‘Supermarkets’ is plural, so the plural form ‘are being built’ is required.
Consequently, we would not write ‘a lot of new supermarkets is being built…’ at all.
A new supermarket is being built…
some/a lot of/several/a number of, etc. new supermarkets are being built…
We would use ‘is’ with singular/uncountable nouns:
A lot of money is being wasted.
A lot of work is unnecessary.
Hence:
A lot of the brickwork is exposed.
A lot of the bricks are exposed.
It depends on what noun comes after ‘a lot of’, which takes a plural verb for a plural noun and a singular verb for a singular noun as explained.
Exactly.
Saneta, you can also use ‘lots of’ (usually informal) which when used with a count noun will take a plural verb and with a non-count noun a singular verb. In the latter case, it is taken together with the noun (‘lots of water’, ‘lots of love’ etc) so it is singular.
Which are exactly the same plural/singular/non count rules as already outlined.
Thank you everybody so much…
Have a good, blessed night 
Welcome! I thank you as well. HAND!