Is there a difference between “poco” and “un poco”?

Question

In English, there's a subtle but definite difference between few and a few:

A few men went to the party. (Some people went)

Few men went to the party. (Nobody or almost nobody went)

Does this difference also exist between the un poco and poco of Spanish?

Answer 1

Yes, there is the same difference and then a bit more.

We could translate your examples into Spanish as follows:

A few men went to the party --> A la fiesta fueron unos pocos hombres.

Few men went to the party --> A la fiesta fueron pocos hombres.

In the first example we'd probably say algunos hombres, but unos pocos hombres is usable, too. The meaning of these sentences are basically the same as in English.

Then, we also have a difference between poco and un poco. In this case, poco works as an adverb and may be translated as little in English, though this translation does not always work too well.

For instance:

Pon un poco de azúcar sobre la tarta --> Put a little sugar over the cake

Pon poco azúcar sobre la tarta --> Don't put much sugar over the cake

The general meaning is similar, but un poco can be considered opposed to nothing, while poco is opposed to a lot. In both cases it is an amount between nothing and a lot, but the gist is different.

Answer 2

Yes, I think that subtle difference is also present in Spanish. I think the best example is this:

Durmió poco. (He didn't sleep enough.)

Durmió un poco. (He at least slept some time.)

You can see this difference even in the DRAE, in the definition of poco:

POCO: En número, cantidad o intensidad escasos respecto de lo regular, ordinario o preciso.

UN POCO: Una cantidad pequeña.

The difference is that if you say just poco, you're implying you have a scale and that the amount you are measuring didn't reach a expected level (escasos respecto de lo regular). If you say un poco you don't have that scale, you're just implying a small amout.