Para un curso académico lo correcto es indicar que FEWER (comparativo de FEW) se usa únicamente con sustantivos contables en plural y LESS (comparativo de LITTLE) se usa con sustantivos no contables. Sin embargo, en el inglés coloquial, hablado o conversacional, se utiliza más LESS que FEWER, aunque sea con sustantivos en plural.

1.

There are

  fewer
  too many

police officers in the streets of Buenos Aires.

2.

There should be

  fewer

cars in Mexico, D.F.

3.

There isn't

  enough

public transportation in Panamá.

4.

The governments need to build

  more
  fewer

highways in the cities.

5.

There should be

  less

noise in Santiago de Chile.

6.

We should have

  more

public parking garages in Venezuela.

7.

There is

  too much

air pollution in New York and Paris.

8.

There are

  more
  fewer

cars parked on the streets nowadays.