Could anyone please tell me where is “an” before everyday in the second sentence? Please do not fail to notice “a” before “suitable” in the second sentence.
1- It is not a suitable conversation.
2- In everyday conversation such words should not
be used.
That’s an easy question.
You use “an” when the noun after “everday” is both singular and countable. In your example you used conversation as an uncountable noun.
Haven’t you seen something in your Readers Digests about heros? Isn’t there a regular section about “everyday heros”?
Right. If you use the word “conversation” to talk about that kind of activity in general and then it’s uncountable.
If you refer to a specific conversation (or two specific conversations, etc.), then the word “conversation” is countable.
By the way, the same is true of some other words, e.g., the word “experience”. That can also be both countable and uncountable. It’s uncountable when you use it as a “collective” noun, and countable when you refer to individual/specific experiences.