Yes, but I would use "will". Who waits for two and a half hours on the phone?
The operator is asking me to hold on the phone for another half hr. I say:
How much longer will/would I have to wait? I've been waiting for over 2 hours!
Are both okay?
They just kept putting me on hold...
Last edited by 2006; 31-May-2014 at 02:12. Reason: correct grammar error
You can say, "How much longer do I have to wait?", "How much longer are you going to make me wait?" These are less polite, but at this stage politeness might not be your priority.
Whoever it is you were trying to speak to, I suggest you find another supplier. One who answers the phone in a reasonable length of time.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.