SN4 ""

No	Pattern	Freq
1	[noun] could be account for	10
2	[noun sg] could be account for	7
3	[det] could be account for	6
4	[adj] could be account for	6
5	this could be account for	5
6	this could be account for	5
7	could [adv] be account for	8
8	could not be account for	5
9	could not be account for	5
10	could [not/n't] be account for	5
11	could be [vb pp] account for	5
12	could be [verb] account for	5
13	could be account for [prep]	16
14	could be account for [prep]	16
15	could be account for by	13
16	could be account for by	13