SN4 ""

No	Pattern	Freq
1	it be difficult [to-vb] [adj]	245
2	it is difficult [to-vb] [adj]	193
3	it be difficult [to-vb] [det]	142
4	it be difficult [to-vb] [adj]	98
5	it be difficult [to-vb] any	46
6	it be difficult [to-vb] any	46
7	it was difficult [to-vb] [adj]	36
8	it be difficult [to-vb] this	27
9	it be difficult [to-vb] this	27
10	it be difficult [to-vb] that	20
11	it be difficult [to-vb] that	20
12	it be difficult to find [adj]	18
13	it be difficult [to-vb] these	17
14	it be difficult [to-vb] these	17
15	it 's difficult [to-vb] [adj]	16
16	it be difficult [to-vb] such	14
17	it be difficult [to-vb] such	14
18	it be difficult to imagine [adj]	12
19	it be difficult to see [adj]	11
20	it be difficult to get [adj]	11
21	it be difficult to obtain [adj]	10
22	it be difficult to accept [adj]	7
23	it be difficult to make [adj]	6
24	it be difficult [to-vb] precise	6
25	it be difficult to distinguish [adj]	6
26	it be difficult to reconcile [adj]	6
27	it be difficult [to-vb] precise	6
28	it be difficult [to-vb] accurate	5
29	it be difficult [to-vb] accurate	5
30	it be difficult to give [adj]	5