乾く and 乾かす: being dry and drying something
Compare laundry or hair becoming dry with the act of drying it, and interpret a not-yet-dry state accurately.
Check whether something is dry
洗濯物はもう乾きました。 says that the laundry is already dry. 乾く, read かわく, describes loss of moisture and has the te-form 乾いて.
まだ乾いていないので、着られません。 means that it is not dry yet, so it cannot be worn. Read まだ with the negative to see that the dry state has not yet been reached.
Use a tool to dry something
ドライヤーで髪を乾かしました。 says that someone dried their hair with a hair dryer. 乾かす, read かわかす, takes を for what is dried and で for the tool.
自然に乾くまで待ちます。 means that the speaker will wait until it dries naturally. 乾く describes the change even when nobody actively dries the object.
The similar-sounding 渇く
喉が渇きました。 expresses thirst. The reading is also かわく, but thirst is written 渇く, unlike 乾く for laundry drying.
乾かしてからしまってください。 asks someone to dry the item before putting it away. The requested order is drying first, not storing it while wet.
Is the laundry already dry if someone says まだ乾いていません?
Show the answer and why
No. まだ with ていません indicates that it has not become dry yet.