Student or Learner
I wouldn't pronounce the first a in go ahead, would you please?
If you don't pronounce the initial "a", you're just saying "head", a completely different word.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
(Not a Teacher)
Let's put it this way. There's a big difference between "getting ahead" and "getting head".