II. back [bæk] 副
back [bæk]
| I | back | 
|---|---|
| you | back | 
| he/she/it | backs | 
| we | back | 
| you | back | 
| they | back | 
| I | backed | 
|---|---|
| you | backed | 
| he/she/it | backed | 
| we | backed | 
| you | backed | 
| they | backed | 
| I | have | backed | 
|---|---|---|
| you | have | backed | 
| he/she/it | has | backed | 
| we | have | backed | 
| you | have | backed | 
| they | have | backed | 
| I | had | backed | 
|---|---|---|
| you | had | backed | 
| he/she/it | had | backed | 
| we | had | backed | 
| you | had | backed | 
| they | had | backed | 
