| I | stiffen |
|---|---|
| you | stiffen |
| he/she/it | stiffens |
| we | stiffen |
| you | stiffen |
| they | stiffen |
| I | stiffened |
|---|---|
| you | stiffened |
| he/she/it | stiffened |
| we | stiffened |
| you | stiffened |
| they | stiffened |
| I | have | stiffened |
|---|---|---|
| you | have | stiffened |
| he/she/it | has | stiffened |
| we | have | stiffened |
| you | have | stiffened |
| they | have | stiffened |
| I | had | stiffened |
|---|---|---|
| you | had | stiffened |
| he/she/it | had | stiffened |
| we | had | stiffened |
| you | had | stiffened |
| they | had | stiffened |
单语范例（未经PONS编辑处理）
The two layers would be held together by iron studs, and the structure might be strengthened and stiffened with iron bands.
en.wikipedia.org He seemed to stiffen and come to a pause.
en.wikipedia.org Later, the wool was put into hot water before being used, which shrunk, stiffened, and tightened the wool.
en.wikipedia.org Stiffening resistance east of the canal proved that only a surprise attack had the possibility of ending in victory.
en.wikipedia.org The chassis was stiffened and the engine moved forwards to give more passenger room.
en.wikipedia.org