SN4 ""

No	Pattern	Freq
1	it be difficult [to-vb] [adj]	245
2	it is difficult [verb] [adj]	193
3	it be difficult [verb] [det]	142
4	it be difficult [verb] [adj]	99
5	it be difficult [verb] any	46
6	it be difficult [verb] any	46
7	it was difficult [verb] [adj]	37
8	it be difficult [verb] this	27
9	it be difficult [verb] this	27
10	it be difficult [verb] that	20
11	it be difficult [verb] that	20
12	it be difficult to find [adj]	18
13	it be difficult find [adj]	18
14	it be difficult [verb] these	17
15	it be difficult [verb] these	17
16	it 's difficult [verb] [adj]	16
17	it be difficult [verb] such	14
18	it be difficult [verb] such	14
19	it be difficult get [adj]	12
20	it be difficult to imagine [adj]	12
21	it be difficult imagine [adj]	12
22	it be difficult to get [adj]	11
23	it be difficult to see [adj]	11
24	it be difficult see [adj]	11
25	it be difficult to obtain [adj]	10
26	it be difficult obtain [adj]	10
27	it be difficult accept [adj]	7
28	it be difficult to accept [adj]	7
29	it be difficult [verb] precise	6
30	it be difficult to distinguish [adj]	6