Translation:The cat is on the chair.
This is the difference between traditional Chinese and simplified Chinese. "貓在椅子上。" is traditional Chinese while "猫在椅子上。" is the simplified one.
The difference shows how simplified Chinese fails to show how the composition of the character delivers the meaning of the character. In traditional Chinese, 豸 means an animal with a long vertebrate. 犭is also about vertebrates, but specifically referring to those in the canine family. So if you take the simplified Chinese seriously, the cat must be a canine!
Yes, but it also shows the efficiency of the simplified writing system as it reduces the number of radicals needed to understand the language by making most vertebrates into dogs, thereby asserting the long-known fact that the Chinese language was actually created by ancient canines. True story.
'A cat is on a chair' is a correct answer, should be accepted. There is no context given that would make the sentcence refer to a specific cat on a specific chair.
In fact "A cat..." it is more correct because if you say "The cat" you are being specific so you need "Zhe shi. mao...... or Na shi mao......)
and I don't have a good idea of how to translate "very hard to work into a conversation"... :)