SN4 ""

No	Pattern	Freq
1	[noun] be required to	95
2	[noun sg] be required to	52
3	[noun pl] be required to	36
4	[modal v] be required to	32
5	[vb mod] be required to	32
6	[pron] be required to	30
7	[Wh det] be required to	15
8	will be required to	14
9	will be required to	14
10	[pers pn] be required to	13
11	which be required to	12
12	which be required to	12
13	[verb] be required to	8
14	[adv] be required to	7
15	[noun prp] be required to	6
16	would be required to	6
17	would be required to	6
18	it be required to	5
19	it be required to	5
20	may be required to	5
21	may be required to	5
22	have be required to	5
23	[conj] be required to	5
24	be [adv] required to	25
25	be [adv] required to	16
26	be not required to	9
27	be [not/n't] required to	9
28	be not required to	9
29	be required [verb] to	62
30	be required [to-vb] to	55