SN4 ""

No	Pattern	Freq
1	[adj] is why	1445
2	[det] is why	1438
3	that is why	863
4	that is why	863
5	[pron] is why	598
6	this is why	571
7	this is why	571
8	[Wh det] is why	567
9	which is why	565
10	which is why	565
11	[noun] is why	73
12	[noun sg] is why	65
13	[verb] is why	55
14	[pers pn] is why	27
15	[vb infin] is why	27
16	understand is why	21
17	it is why	21
18	it is why	21
19	understand is why	19
20	question is why	19
21	question is why	18
22	[adv] is why	9
23	[vb pp] is why	8
24	[conj] is why	8
25	[to-vb] is why	8
26	[adv] is why	7
27	[adj] is why	7
28	mystery is why	6
29	know is why	6
30	ask is why	5