
Regular verb: crab - crabbed - crabbed
Simple form | V-ing form | 
| I could crab you could crab he could crab we could crab you could crab they could crab  | I could be crabbing you could be crabbing he could be crabbing we could be crabbing you could be crabbing they could be crabbing  | 
Perfect | V-ing perfect | 
| I could have crabbed you could have crabbed he could have crabbed we could have crabbed you could have crabbed they could have crabbed  | I could have been crabbing you could have been crabbing he could have been crabbing we could have been crabbing you could have been crabbing they could have been crabbing  | 
Simple form | V-ing form | 
| I couldn't crab you couldn't crab he couldn't crab we couldn't crab you couldn't crab they couldn't crab  | I couldn't be crabbing you couldn't be crabbing he couldn't be crabbing we couldn't be crabbing you couldn't be crabbing they couldn't be crabbing  | 
Perfect | V-ing perfect | 
| I couldn't have crabbed you couldn't have crabbed he couldn't have crabbed we couldn't have crabbed you couldn't have crabbed they couldn't have crabbed  | I couldn't have been crabbing you couldn't have been crabbing he couldn't have been crabbing we couldn't have been crabbing you couldn't have been crabbing they couldn't have been crabbing  | 
Simple form | V-ing form | 
| could I crab? could you crab? could he crab? could we crab? could you crab? could they crab?  | could I be crabbing? could you be crabbing? could he be crabbing? could we be crabbing? could you be crabbing? could they be crabbing?  | 
Perfect | V-ing perfect | 
| could I have crabbed? could you have crabbed? could he have crabbed? could we have crabbed? could you have crabbed? could they have crabbed?  | could I have been crabbing? could you have been crabbing? could he have been crabbing? could we have been crabbing? could you have been crabbing? could they have been crabbing?  | 
Simple form | V-ing form | 
| couldn't I crab? couldn't you crab? couldn't he crab? couldn't we crab? couldn't you crab? couldn't they crab?  | couldn't I be crabbing? couldn't you be crabbing? couldn't he be crabbing? couldn't we be crabbing? couldn't you be crabbing? couldn't they be crabbing?  | 
Perfect | V-ing perfect | 
| couldn't I have crabbed? couldn't you have crabbed? couldn't he have crabbed? couldn't we have crabbed? couldn't you have crabbed? couldn't they have crabbed?  | couldn't I have been crabbing? couldn't you have been crabbing? couldn't he have been crabbing? couldn't we have been crabbing? couldn't you have been crabbing? couldn't they have been crabbing?  |