SN4 ""

No	Pattern	Freq
1	[conj] it must be [adv]	42
2	[verb] it must be [adv]	21
3	[coord] it must be [adv]	18
4	[noun] it must be [adv]	13
5	[subord] it must be [adv]	13
6	[adv] it must be [adv]	12
7	[adv] it must be [adv]	12
8	that it must be [adv]	11
9	that it must be [adv]	11
10	[that] it must be [adv]	11
11	[adj] it must be [adv]	10
12	but it must be [adv]	10
13	but it must be [adv]	10
14	[noun sg] it must be [adv]	9
15	and it must be [adv]	8
16	[vb base] it must be [adv]	8
17	and it must be [adv]	8
18	[adj] it must be [adv]	7
19	think it must be [adv]	6
20	it must have be [adv]	120
21	it must [vb infin] be [adv]	120
22	it must [verb] be [adv]	120
23	it must have be [adv]	118
24	it must [adv] be [adv]	17
25	it must [adv] be [adv]	10
26	it must not be [adv]	7
27	it must [not/n't] be [adv]	7
28	it must not be [adv]	6
29	it must of be [adv]	5
30	it must [prep] be [adv]	5