I was wondering why do native people repeat words twice in a row.
eg "He is not 'reading' reading" or "they're 'playing' playing"
The first word is sayed in a slow sarcastic voice. I'm not quite sure what this is supposed to mean.
It means that the action described is not what it appears to be. For example, "He's not _reading_ reading" means "He isn't actually reading in the usual way, although that's what it looks like."
It may or may not be intended sarcastically.
For example, if your very young child seems to be reading intently when in fact he is just pretending to read, you might say to another adult "oh, he's not _reading_ reading—it's just his little make-believe activity."
The previous post matches my usage exactly. You could
say things like "Joe killed Sam accidentally. Joe didn't mean to
__kill him__ kill him. He just meant to try to kill him to scare him,
but he killed him anyway."
I have never - or very infrequently - seen this construction
in writing. In writing you would use a word like "really".
It's hard to convey the meaning just with writing because intonation is essential. You could use italics but using "really" would be more usual in writing. When people write they tend to use a more formal style.
It seems that in parts of the north of England (especially Lancashire) some people repeat what they have just said just as a means to add emphasis to what they've said. If any of you watch Coronation Street on TV you will see a perfect example in Fred, the butcher, who is pretty old. He says things like: "I want you to come to dinner tomorrow night, I say - I want you to come to dinner!" It's quite funny.