| Base form (v1) | Constrain |
| Past form (v2) | Constrained |
| Past Participle (v3) -ed form |
Constrained |
| Present Participle (v4) ‘ing’ form |
Constraining |
| Present simple (v5) s / es/ ies |
Constrains |
Past continuous tense of constrain verb forms - Learn English Free Online
