"Το αγόρι είδε το υποβρύχιο."

Translation: The boy saw the submarine.

[johndelaroo]

Ήταν κίτρινο; Πόσες Beatles έχουν σε αυτό;

[PhilSimmonds]

Usually one spelling mistake is ok. I used 'η' not 'υ' in submarine and got an incorrect.

[slava8]

a submarine is also known as a sub (and easier to type)