SN4 ""

No	Pattern	Freq
1	[adv] [vb mod] have been [adj]	59
2	[adv] [modal v] have been [adj]	57
3	[adv] [modal v] have been [adj]	57
4	[adv] [modal v] have been [adj]	40
5	[adv] would have been [adj]	38
6	[adv] would have been [adj]	37
7	[adv] [modal v] have been [det]	12
8	alone [modal v] have been [adj]	7
9	alone [modal v] have been [adj]	7
10	[adv] must have been [adj]	6
11	[adv] must have been [adj]	6
12	[adv] [modal v] have been enough	6
13	[adv] [modal v] have been enough	6
14	[adv] might have been [adj]	5
15	[adv] [modal v] have been [adj -er]	5
16	[adv] could have been [adj]	5
17	[adv] might have been [adj]	5
18	[adv] could have been [adj]	5