"I dry the plates."
अनुवाद:मैं थालियों को सुखाता हूँ।
'मैं थालियों को सूखता हूँ ।' doesn't fully make sense because there are two verbs here, 'सूखना' and 'सुखाना', which are a little different from each other.
The verb 'सूखना' (which you used) is used when something is drying up. For eg : नदी सूखती है । - The river dries up, थाली सूख रही है । - The plate is drying.
The verb 'सुखाना' (which is used in the above sentence) is used when someone is drying something/someone else. For eg - मैं उसको सुखा रहा हूँ ।- I am drying him up, वह अपने कपड़ों को सुखाता है । - He dries his clothes.
In the above sentence, you are drying up the plates. So you say 'मैं थालियों को सुखाता हूँ ।'