1)little+[u不可数名词] :几乎没有../很少.(表否定意思) There is little water left in the glass.
a little+[u]:一点点(表肯定意思),e.g.THere is a little water left in the glass.
2)little 放句首要部分倒装,因为表示否定:Little does he know about the fact.
3)no a little=quite a little 相当多的...