It is not correct. For sure it misses "for": Here comes an answer why FOR most of... Ans I would write it like this: Here comes an answer why form most of the teenagers... Or: Here comes an answer why for most teenagers... And it has sense: They are going to answer the question: "Why most teenagers do not feel motivated by health. Hope it is helpful.

I don´t think it is correct, and for sure it is not used in English. These are the sentences that I can think of regarding your question. It feels like a long time since I heard from you. (since I last heard from you) It's been a long time since I heard from you. For a very long time I didn't hear from you. Hope it is of any help for you.

Yes I want to help you.

Yes of course my firend. I can talk to you.

Hello Nina, I would be glad to write and speak to you in English. I can also teach you English. Would you like to write and speak to me in German. Thanks.

to watch es mirar con atención, vigilar, pero en la oración que tu citas, ese mirar con atención, lo equivaparan a vigilar o cuidar al bebe esta noche.

Some one in this site has already said it: Impossible is nothing. You can, but it will require a lot of effort from you and help from a good friend.

Hola, mi nombre es Benito y si tú realmente te empeñas, seguro que aquì encontrarás la ayuda necesaria. Por lo pronto cuenta conmigo. Saludos para todos los hermanos guatemaltecos.