For all fairy tail fans: What do te think is the relationship of Zeref to Natsu?Why Zeref knows Natsu's name??

I have seen plenty of viable theories on this floating around the web. My favourite involving the most recente chapter:
Natsu and the other Dragon Slayers are from the past, 400 years approx, the time (or shortly after) the Draghi war. The Draghi seeing Acnologia becoming too powerful for them sent the young Dragon Slayers to the future where they would have a better chance of defeating him and Zeref. The Dragon Slayers we know, likely being the children of the original Dragon Slayers.
Natsu and Zeref share similarities in their appearances, which could possibly mean that they are related somehow, likely father o brother. Assuming this theory is correct, Natsu and Zeref are both from the same time period, so this relationship is very possible.
The matter of why Zeref is evil, and why he believes Natsu is the only one who can stop him is still a complete mystery.
As for the Dragon Slayers not knowing about this, I would assume that either the time-travel somehow damaged their memories o the Draghi deliberately tampered with them.
Also, this would answer the Freed's age barrier question, since they would technically be 400+ years old, they are definitely above 80, so would not pass through the barrier.

Well at first he was revealed to be Zeref's greatest demon creation and the only one powerful enough to kill him, but it soon reveals he is Zeref's little brother. But Natsu clearly has no memory of Zeref.

no clue. and it's pissing me off 'cuz i'm usually good at solving things like this.
i pretty much predicted the whole otturatore, dell'otturatore Island movie... but this is freakin' impossible!

we all figure it must be something from natsu's past....zerof detto the words ''only natsu can stop me'' meaning either he IS natsu's father o natsu has più going for him then we previously thought

I think they are related cause they both are dragon slayers. :) Zeref's dragon is Acnologia I think.:)
Maybe Zeref is a dragon slayer too :)Remember how Natsu knew Wendy's name before they met :) they both were dragon slayers so may be Zeref knew Natsu cause he was a dragon slayer too. :)
I know my imagination is crazy but I hope te like my answer :)

I have no idea.

Natsu is Zeref's little brother who died at a young age. Zeref's full name is Zeref Dragneel. Igneel could'nt kill Natsu so he train him and wished he would'nt turn out like Zeref

I've only seen up to 175 episodes of Fairy Tail, but from my under standing Natsu isn't E.N.D, but he dose have some connection to Zeref. One of the beliefs is that Zeref is Natsu's future existence but that is not in any way possible, the secondo belief is that Natsu is Zeref's son. this makes più sence to me because they do share some characteristics, but Natsu is an inch taller, & his muscles are much larger than Zeref's. So my thought is that when Zeref finally had a sane personality, and was able to controle his power before he started isolating himself, he had relations with a woman (Natsu's berth mother, who we do not know yet), & Natsu was born. i figure that when Natsu was very young either his mother abandoned him and Zeref, o she died once Zeref started to lose controle of his power. knowing what could happen to his son he entrusted Natsu to Igneele (Natsu's adopted father) for him to train, and raise. after leaving Natsu we know he ventured into the world and joined the Fairy tail guild, and after the Tower Of Heaven, & everything that followed to the S-class wizard trial on Tenro island, Natsu met Zeref not knowing who he was. but it seemed as though Zeref knew Natsu prety well. So there fore my theory is that Zeref is Natsu's Berth father and being blood to him, he belives that Natsu is the only one who can defeat him for good!

It detto in the manga that natsu and zeroed r siblings