Student or Learner
1) "Come online to Yahoo!" is correct?
2) "I want to see you on the web cam OR through the web cam." ?
3) "Write it on your notebook OR in your notebook." ?
4) "Did you go to photocopy these documents?" Correct?
5) "I put your letter under the keyboard, pick it from there." Correct
Many thanks in advance
***Not a teacher***
Internet/computing language is often idiomatic and full of technically acceptable phrases that may not appear gramatially correct - so lots of things are acceptable in this sort of speech.1) "Come online to Yahoo!" is correct?
I may just say 'Go online to Yahoo', or more likely in a conversation about computing with someone who was familiar with using a web browser 'Go to Yahoo'. A more verbose way of putting it would be "Open a browser and navigate to Yahoo". I would not generally use 'Come online...'.
Again, it's quite idiomatic, but I'd probably say "I want to see you on the web cam", "Let's Skype via web cam" etc2) "I want to see you on the web cam OR through the web cam." ?
'In your notebook' if you are talking about the paper type (rather than an HP Notebook) - unless you want someone to write on the cover (e.g.write your name on your notebook').3) "Write it on your notebook OR in your notebook." ?
You can say this, although the 'go to + verb' construction is probably less likely here than some others, unless you want to emphasize the 'going' element of the sentence for some reason. In other words:4) "Did you go to photocopy these documents?" Correct?
'Did you photocopy these documents?' might be more likely
'Did you go to the bank?' is ok (go to + article + noun)
I assume you didn't mean 'Did you get to photocopy these documents?', meaning 'did you manage to get round to photocopying these documents?'
Not quite - either '...pick it up from there', or '...get it from there.' Also I would probably use a semi-colon rather than a comma in that sentence.5) "I put your letter under the keyboard, pick it from there." Correct