I. sign [saın] 名词
II. sign [saın] 动词 trans
| I | sign | 
|---|---|
| you | sign | 
| he/she/it | signs | 
| we | sign | 
| you | sign | 
| they | sign | 
| I | signed | 
|---|---|
| you | signed | 
| he/she/it | signed | 
| we | signed | 
| you | signed | 
| they | signed | 
| I | have | signed | 
|---|---|---|
| you | have | signed | 
| he/she/it | has | signed | 
| we | have | signed | 
| you | have | signed | 
| they | have | signed | 
| I | had | signed | 
|---|---|---|
| you | had | signed | 
| he/she/it | had | signed | 
| we | had | signed | 
| you | had | signed | 
| they | had | signed |