SN4 ""

No	Pattern	Freq
1	[vb mod] have heard	330
2	[modal v] have heard	330
3	[adv] have heard	90
4	would have heard	77
5	must have heard	75
6	must have heard	75
7	would have heard	61
8	may have heard	54
9	may have heard	54
10	[adv] have heard	51
11	will have heard	49
12	not have heard	39
13	[not/n't] have heard	39
14	will have heard	34
15	might have heard	28
16	might have heard	28
17	could have heard	23
18	could have heard	23
19	should have heard	22
20	should have heard	22
21	not have heard	20
22	n't have heard	19
23	'd have heard	16
24	'll have heard	15
25	never have heard	14
26	never have heard	14
27	[pers pn] have heard	8
28	[pron] have heard	8
29	possibly have heard	6
30	possibly have heard	6