
Regular verb: suffer - suffered - suffered
Simple form | V-ing form | 
| I can suffer you can suffer she can suffer we can suffer you can suffer they can suffer  | I can be suffering you can be suffering she can be suffering we can be suffering you can be suffering they can be suffering  | 
Perfect | V-ing perfect | 
| I can have suffered you can have suffered she can have suffered we can have suffered you can have suffered they can have suffered  | I can have been suffering you can have been suffering she can have been suffering we can have been suffering you can have been suffering they can have been suffering  | 
Simple form | V-ing form | 
| I can't suffer you can't suffer she can't suffer we can't suffer you can't suffer they can't suffer  | I can't be suffering you can't be suffering she can't be suffering we can't be suffering you can't be suffering they can't be suffering  | 
Perfect | V-ing perfect | 
| I can't have suffered you can't have suffered she can't have suffered we can't have suffered you can't have suffered they can't have suffered  | I can't have been suffering you can't have been suffering she can't have been suffering we can't have been suffering you can't have been suffering they can't have been suffering  | 
Simple form | V-ing form | 
| can I suffer? can you suffer? can she suffer? can we suffer? can you suffer? can they suffer?  | can I be suffering? can you be suffering? can she be suffering? can we be suffering? can you be suffering? can they be suffering?  | 
Perfect | V-ing perfect | 
| can I have suffered? can you have suffered? can she have suffered? can we have suffered? can you have suffered? can they have suffered?  | can I have been suffering? can you have been suffering? can she have been suffering? can we have been suffering? can you have been suffering? can they have been suffering?  | 
Simple form | V-ing form | 
| can't I suffer? can't you suffer? can't she suffer? can't we suffer? can't you suffer? can't they suffer?  | can't I be suffering? can't you be suffering? can't she be suffering? can't we be suffering? can't you be suffering? can't they be suffering?  | 
Perfect | V-ing perfect | 
| can't I have suffered? can't you have suffered? can't she have suffered? can't we have suffered? can't you have suffered? can't they have suffered?  | can't I have been suffering? can't you have been suffering? can't she have been suffering? can't we have been suffering? can't you have been suffering? can't they have been suffering?  |