Question

I don't think so.与 I think not.有何区别

Answer 1

两者的区别在句子用法的不同。
区别一
情景不同
I
don't
think
so
一般是在别人提出观点后就此观点提出自己的意见
I
think
not
一般是直接从个人观点出发的.
区别二
否定词表示意义不同
a.I
don't
think
it
is
a
good
idea.
b.I
think
it
isn't
a
good
idea.
a是由否定词提升转换规则把b的宾语从句中的not转移到母句中的结果。
区别三
句子意义
I
don't
think....句式表达两种意义，not否定整个句子表达的命题，此时don't一般要重读
not否定宾语从句表达的命题，因此不难看出是不同义的。
Will
they
come
tomorrow
?
I
don't
think
so
=I
doubt
whether
they
will.
I
think
not
=I'm
definitely
sure
they
will
not.

Answer 2

I
don't
think
so.
翻译为：我不认为这样（一般接上文内容）。
I
think
not.
这句英语不地道，一般不这么用。