te/demo and noni

[jampanman]

Dear mina-san,

Am I correct in thinking there is some these grammatical forms overlap each other in usage.

For example:
メールしても、返事が書いてこない
メールしたのに、返事が書いてこない

What the difference between the above.

Thanks ahead.

[QuackingShoe]

返事が書いてこない doesn't make sense, it should be 返事がこない or something.

Anyway, setting that aside. They give very impressions. ても has got that も in there, and gives you that "Even if I do this... (also if I don't)" impression. Comparatively, it seems like more of a simple statement of fact. のに sounds significantly more like actual complaining. It's directly counter to expectations, and in most emotional contexts actually sounds directly sulky.
That's not to say ても can't be emotional. がんばってもがんばっても is a common enough way of expressing yourself, but it gives a different impression than がんばったのに.

All of this is aimed specifically at situations where you could theoretically use either. There are, of course, a lot of instances where they have nothing to do with each other. They function differently grammatically.　Anywho, keep immersing in Japanese stuff and you'll get used to it...

[jampanman]

Thanks for your post, I found it very helpful.

With regards to the 'kaitekonai' I'm not actually sure if the verb being used here is 書く but when talking about emails/sms this is what my Japanese friends often say. Do you have any ideas what verb is actually is?

Thanks ahead

[Jessi]

It sounds like your friends are saying 返ってこない

I'd also like to add that メールしたのに sounds like you're talking about a specific incident/one-time occurence. メールしても makes it sound like you never get a reply ever.