SN4 ""

No	Pattern	Freq
1	it be impossible	1565
2	it [be] impossible	1565
3	it [is] impossible	993
4	it is impossible	812
5	it [was/were] impossible	562
6	it was impossible	561
7	it 's impossible	181
8	it [adv] impossible	133
9	it [adv] impossible	132
10	it [verb] impossible	125
11	it [vb past] impossible	77
12	it seem impossible	69
13	it almost impossible	66
14	it almost impossible	66
15	it [vb -s] impossible	45
16	it seemed impossible	42
17	it virtually impossible	32
18	it virtually impossible	32
19	it prove impossible	26
20	it seems impossible	25
21	it become impossible	23
22	it proved impossible	22
23	it becomes impossible	12
24	it became impossible	11
25	it quite impossible	9
26	it quite impossible	9
27	it [be] impossible	6
28	it be impossible	6
29	[verb] it impossible	504
30	make it impossible	300