SN4 ""

No	Pattern	Freq
1	[pron] could have been [verb] for	29
2	[pers pn] could have been [verb] for	26
3	[noun] could have been [verb] for	25
4	[noun sg] could have been [verb] for	10
5	you could have been [verb] for	8
6	[noun pl] could have been [verb] for	8
7	you could have been [verb] for	8
8	[noun prp] could have been [verb] for	7
9	she could have been [verb] for	5
10	[adj] could have been [verb] for	5
11	she could have been [verb] for	5
12	could [adv] have been [verb] for	15
13	could [adv] have been [verb] for	9
14	could not have been [verb] for	6
15	could not have been [verb] for	6
16	could [not/n't] have been [verb] for	6
17	could have been [verb] for [v-ing]	18
18	could have been [verb] for [verb]	18
19	could have been [verb] for [noun]	14
20	could have been [verb] for [art]	14
21	could have been [verb] for [art]	14
22	could have been [verb] for [pron]	11
23	could have been [verb] for a	8
24	could have been [verb] for [noun sg]	7
25	could have been [verb] for [adj]	7
26	could have been [verb] for the	6
27	could have been [verb] for a	6
28	could have been [verb] for the	6
29	could have been [verb] for [det]	5
30	could have been [verb] for [pers pn]	5