SN4 ""

No	Pattern	Freq
1	[verb] how difficult it [be]	58
2	[vb base] how difficult it [be]	15
3	[prep] how difficult it [be]	14
4	[vb past] how difficult it [be]	14
5	[prep] how difficult it [be]	14
6	know how difficult it [be]	12
7	know how difficult it [be]	9
8	[to-vb] how difficult it [be]	8
9	[adv] how difficult it [be]	7
10	[conj] how difficult it [be]	7
11	and how difficult it [be]	7
12	[coord] how difficult it [be]	7
13	and how difficult it [be]	7
14	[adj] how difficult it [be]	6
15	[vb -s] how difficult it [be]	6
16	about how difficult it [be]	6
17	about how difficult it [be]	6
18	[adj] how difficult it [be]	6
19	[v-ing] how difficult it [be]	6
20	of how difficult it [be]	5
21	[vb pp] how difficult it [be]	5
22	of how difficult it [be]	5
23	explain how difficult it [be]	5
24	[pron] how difficult it [be]	5
25	how [adv] difficult it [be]	5
26	how [adv] difficult it [be]	5
27	how difficult it [modal v] [be]	25
28	how difficult it [vb mod] [be]	25
29	how difficult it can [be]	9
30	how difficult it would [be]	9