| 空 |
kōng dòng | cavity / empty / vacuous |
| 空 |
kōng | empty / air / sky / in vain |
| 空 |
kòng | to empty / vacant / unoccupied / space / leisure / free time |
| 洞 |
dòng | cave / hole / zero (unambiguous spoken form when spelling out numbers) / CL:个 |
| 洞 |
tóng | used in 洪洞, a county in Shanxi |