When I first encountered กล้องถ่ายรูป I couldn't read Thai and I knew about tones tones but typically, often got them wrong.  I knew that *กลอง was a box so that made a camera a 'box camera' which was the basic camera of my youth and this misconception persisted long after I had learned to read and write.  I was never really sure between box and camera,

 I suppose if กล้อง and ถ่ายรูป are taught separately now this problem Is not one shared by new learners but perhaps it shows the value of basic Thai.  For example when encountering telescope, binoculars theodolite etc. does camera or tube spring to mind which is the more useful?   


 
Anyone got any similar useful misconceptions?  

I picked up the expression 'tang tek' to mean broke, no money.

Useful expression I thought, so I started using it saying ตังค์แตก as in 'money broke'

 

I was beginning to give up using it because I was not getting much in response........until I read

ถังแตก in a book 'tank broken'.  It made a huge difference!

That's a good one.
A girlfriend once said "kiss me", I thought, how sweet and obliged, she appeared surprised.  Years later when I had learned of the difficulty some English words present I realized that she has said Excuse me! My response would have been "sweet" too had she not meant What did you say!