conversation在多数情况下是可数的，泛指谈话时是不可数名词。与动词have，hold等连用时，要加不定冠词，但与动词make连用时不加不定冠词。作主语或作介词宾语时也不加不定冠词，但有形容词修饰时要加不定冠词。in conversation with是属介词短语的词组。
conversation双语例句
I'm learning English conversation.
我正在学英语会话。
None of them can carry out even the simplest conversation in the foreign language they have been learning.
他们当中没有谁能用所学的外语进行即便（是）最简单的会话。
I had a long conversation with her the other day.
前几天我与她作了一次长谈。
The main topic of conversation was Tom's new girlfriend.
交谈的主要话题是汤姆的新女友。
Don was deep in conversation with the girl on his right.
唐与他右边的女孩在专心交谈。