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