
Verbo regular: fasten - fastened - fastened
Forma simple | Forma con V-ing | 
| I'd fasten you'd fasten he'd fasten we'd fasten you'd fasten they'd fasten  | I'd be fastening you'd be fastening he'd be fastening we'd be fastening you'd be fastening they'd be fastening  | 
Perfecto | Perfecto con V-ing | 
| I should've fastened you should've fastened he should've fastened we should've fastened you should've fastened they should've fastened  | I should've been fastening you should've been fastening he should've been fastening we should've been fastening you should've been fastening they should've been fastening  | 
Forma simple | Forma con V-ing | 
| I shouldn't fasten you shouldn't fasten he shouldn't fasten we shouldn't fasten you shouldn't fasten they shouldn't fasten  | I shouldn't be fastening you shouldn't be fastening he shouldn't be fastening we shouldn't be fastening you shouldn't be fastening they shouldn't be fastening  | 
Perfecto | Perfecto con V-ing | 
| I shouldn't have fastened you shouldn't have fastened he shouldn't have fastened we shouldn't have fastened you shouldn't have fastened they shouldn't have fastened  | I shouldn't have been fastening you shouldn't have been fastening he shouldn't have been fastening we shouldn't have been fastening you shouldn't have been fastening they shouldn't have been fastening  | 
Forma simple | Forma con V-ing | 
| should I fasten? should you fasten? should he fasten? should we fasten? should you fasten? should they fasten?  | should I be fastening? should you be fastening? should he be fastening? should we be fastening? should you be fastening? should they be fastening?  | 
Perfecto | Perfecto con V-ing | 
| should I have fastened? should you have fastened? should he have fastened? should we have fastened? should you have fastened? should they have fastened?  | should I have been fastening? should you have been fastening? should he have been fastening? should we have been fastening? should you have been fastening? should they have been fastening?  | 
Forma simple | Forma con V-ing | 
| shouldn't I fasten? shouldn't you fasten? shouldn't he fasten? shouldn't we fasten? shouldn't you fasten? shouldn't they fasten?  | shouldn't I be fastening? shouldn't you be fastening? shouldn't he be fastening? shouldn't we be fastening? shouldn't you be fastening? shouldn't they be fastening?  | 
Perfecto | Perfecto con V-ing | 
| shouldn't I have fastened? shouldn't you have fastened? shouldn't he have fastened? shouldn't we have fastened? shouldn't you have fastened? shouldn't they have fastened?  | shouldn't I have been fastening? shouldn't you have been fastening? shouldn't he have been fastening? shouldn't we have been fastening? shouldn't you have been fastening? shouldn't they have been fastening?  |