La diferencia entre little y few es la misma que entre much y many. Little describe una cantidad pequeña de un sustantivo incontable, mientras que few significa un número pequeño de un sustantivo contable. Several de otro lado describe una cantida desconocida de un sustantivo contable.

El uso de much y many
little poco (singular!)
few pocos (plural!)
several algunos
a) Little y few se usan sobre todo en frases afirmativas.
b) Se pueden utilizar sin o con artículo .
Ejemplo
a) We hoped, we would win a little money in the lottery.
a) She has only a few friends left; all others moved to other cities.
a)Several of our cups broke when we had our last party.
b)There used to be much free space. Now there is only little of it to be seen.
b)Few of my colleagues ever ran a marathon.