
Regular verb: introduce - introduced - introduced
Simple form | V-ing form | 
| I could introduce you could introduce she could introduce we could introduce you could introduce they could introduce  | I could be introducing you could be introducing she could be introducing we could be introducing you could be introducing they could be introducing  | 
Perfect | V-ing perfect | 
| I could have introduced you could have introduced she could have introduced we could have introduced you could have introduced they could have introduced  | I could have been introducing you could have been introducing she could have been introducing we could have been introducing you could have been introducing they could have been introducing  | 
Simple form | V-ing form | 
| I couldn't introduce you couldn't introduce she couldn't introduce we couldn't introduce you couldn't introduce they couldn't introduce  | I couldn't be introducing you couldn't be introducing she couldn't be introducing we couldn't be introducing you couldn't be introducing they couldn't be introducing  | 
Perfect | V-ing perfect | 
| I couldn't have introduced you couldn't have introduced she couldn't have introduced we couldn't have introduced you couldn't have introduced they couldn't have introduced  | I couldn't have been introducing you couldn't have been introducing she couldn't have been introducing we couldn't have been introducing you couldn't have been introducing they couldn't have been introducing  | 
Simple form | V-ing form | 
| could I introduce? could you introduce? could she introduce? could we introduce? could you introduce? could they introduce?  | could I be introducing? could you be introducing? could she be introducing? could we be introducing? could you be introducing? could they be introducing?  | 
Perfect | V-ing perfect | 
| could I have introduced? could you have introduced? could she have introduced? could we have introduced? could you have introduced? could they have introduced?  | could I have been introducing? could you have been introducing? could she have been introducing? could we have been introducing? could you have been introducing? could they have been introducing?  | 
Simple form | V-ing form | 
| couldn't I introduce? couldn't you introduce? couldn't she introduce? couldn't we introduce? couldn't you introduce? couldn't they introduce?  | couldn't I be introducing? couldn't you be introducing? couldn't she be introducing? couldn't we be introducing? couldn't you be introducing? couldn't they be introducing?  | 
Perfect | V-ing perfect | 
| couldn't I have introduced? couldn't you have introduced? couldn't she have introduced? couldn't we have introduced? couldn't you have introduced? couldn't they have introduced?  | couldn't I have been introducing? couldn't you have been introducing? couldn't she have been introducing? couldn't we have been introducing? couldn't you have been introducing? couldn't they have been introducing?  |