Total verb forms: 51
| Imperatives and participles |
| Present Participle | stiffening |
| Present Participle | stiffened |
| Imperative | stiffen |
| Type | I | you | he/she/it | we | you | they |
| Present | stiffen | stiffen | stiffens | stiffen | stiffen | stiffen |
| Past | stiffened | stiffened | stiffened | stiffened | stiffened | stiffened |
| Future | will stiffen | will stiffen | will stiffen | will stiffen | will stiffen | will stiffen |
| Present conditional | would stiffen | would stiffen | would stiffen | would stiffen | would stiffen | would stiffen |
| Past conditional | would have stiffened | would have stiffened | would have stiffened | would have stiffened | would have stiffened | would have stiffened |
| Present Perfect | have stiffened | have stiffened | has stiffened | have stiffened | have stiffened | have stiffened |
| Past Perfect | had stiffened | had stiffened | had stiffened | had stiffened | had stiffened | had stiffened |
| Future Perfect | will have stiffened | will have stiffened | will have stiffened | will have stiffened | will have stiffened | will have stiffened |
Conjugated verbs before and after stiffen
