There ____ aTV in the classroo

In this sentence you have to say:

There is not a TV in the classroom.

If you want to use "is no", you have to say:

There is NO TV in the classroom

2011-11-24 16:32:09 補充：
"not" is an adverb, it is used to describe "is".
"no" is an adjective, it is use to describe "TV".

2011-11-24 16:38:18 補充：
no, your understanding is not exactly right !
adverb can only be used to describe verb, and addjective can only be used to describe noun. Both have nothing to do with number !

2011-11-24 17:11:47 補充：
"adverb" is 副詞 and "adjective" is 形容詞

no是形容詞，no後面接的是名詞不是冠詞！

There is no TV in the room. (O)
There is not a TV in the room. (O)
There is no a TV in the room. (X)
There is not TV in the room. (X)

一般來說大多數講 There is no TV in the room，很少會說 There is not a TV in the room.

1. There is是[有}
2. There is not是[沒有]
3. a TV一台電視
4. no TV沒有電視
1+4的結果就是沒有電視
no這個字是由not one演變成non,然後再變成no的(請參見<遠東新世紀英漢辭典>no的字源說明.)