could have past participle

Points 140, 142, 158, 176 and 214 in the category of MODALITY are used for PAST POSSIBILITY, SPECULATION, REGRET, CRITICISM.

On the Left, iWeb corpus gives us the following past participles:

1 COULD HAVE BEEN 178902

On the right further collocations, 4 to the left and right are from COCA corpus:
1 WORSE (JJR ) 542

2 AVOIDED (VVN ) 464

3 PREVENTED (VVN ) 357
4 KILLED (VVN ) 278
5 WISH (VV0 ) 227

6 EASILY (RR ) 155

7 SAVED (VVN ) 145
8 CAUSED (VVN ) 93
9 HANDLED (VVN ) 88
10 ANYWHERE (RL ) 87

2 COULD HAVE DONE 32180

1 SOMETHING (PN1 ) 322

2 BETTER (RRR ) 262

3 THING (NN1 ) 217
4 WITHOUT (IW ) 206
5 NOTHING (PN1 ) 203
6 THINGS (NN2 ) 200
7 JOB (NN1 ) 174
8 ANYTHING (PN1 ) 167
9 DIFFERENTLY (RR ) 159
10 ELSE (RR ) 136

3 COULD HAVE HAD 14021
4 COULD HAVE MADE 13903
5 COULD HAVE GONE 12542
6 COULD HAVE USED 11385
7 COULD HAVE GOTTEN 7978
8 COULD HAVE HAPPENED 7390
9 COULD HAVE TAKEN 6741
10 COULD HAVE IMAGINED 6702
11 COULD HAVE COME 5235
12 COULD HAVE SAVED 5064
13 COULD HAVE CAUSED 4276
14 COULD HAVE SEEN 3691
15 COULD HAVE GIVEN 3464
16 COULD HAVE SAID 3415
17 COULD HAVE GOT 3403
18 COULD HAVE WON 3066
19 COULD HAVE WRITTEN 3016
20 COULD HAVE PUT 2970