SN4 ""

No	Pattern	Freq
1	[adv] [vb mod] have been [adj]	57
2	[adv] [modal v] have been [adj]	55
3	[adv] [modal v] have been [adj]	39
4	[adv] would have been [adj]	36
5	[adv] would have been [adj]	35
6	[adv] [modal v] have been [det]	11
7	alone [modal v] have been [adj]	7
8	[adv] [modal v] have been enough	6
9	[adv] [modal v] have been enough	6
10	[adv] must have been [adj]	6
11	[adv] must have been [adj]	6
12	[adv] could have been [adj]	5
13	[adv] might have been [adj]	5
14	[adv] [modal v] have been [adj -er]	5
15	[adv] could have been [adj]	5
16	[adv] might have been [adj]	5