SN4 ""

No	Pattern	Freq
1	[verb] [adv] have to	998
2	do [adv] have to	920
3	[vb base] [adv] have to	491
4	do [adv] have to	465
5	[modal v] [adv] have to	362
6	[vb mod] [adv] have to	362
7	[vb -s] [adv] have to	334
8	does [adv] have to	318
9	[pron] [adv] have to	316
10	[noun] [adv] have to	309
11	[pers pn] [adv] have to	245
12	[noun sg] [adv] have to	159
13	will [adv] have to	158
14	[vb past] [adv] have to	149
15	would [adv] have to	136
16	did [adv] have to	135
17	[noun pl] [adv] have to	127
18	would [adv] have to	126
19	[adv] [adv] have to	115
20	will [adv] have to	109
21	it [adv] have to	83
22	it [adv] have to	83
23	[conj] [adv] have to	71
24	[adv] [adv] have to	67
25	[coord] [adv] have to	54
26	you [adv] have to	51
27	you [adv] have to	51
28	and [adv] have to	47
29	[not/n't] [adv] have to	47
30	and [adv] have to	47