(MOE and ZOE are customers sitting in a diner. JOE, the waiter, stands beside them.)
JOE: Would you like coffee?
MOE: Is the coffee here good?
ZOE: It's great. I'll have coffee.
MOE: I'll have a coffee too. I haven't had coffee in a while.
ZOE: Come to think of it, the last time I had a coffee was right here.
JOE: Two coffees. Great.
Moe's question with the coffee is easy enough to understand, because he is talking about the specific coffee of the restaurant. But notice how Zoe later says, "I'll have coffee," and Moe says, "I'll have a coffee." Then Moe says, "I haven't had coffee" and Zoe says, "the last time I had a coffee." Downright confusing, eh?
In their last lines, Zoe and Moe could have added a where they deleted it and deleted a where they said it. This is where the parlance of English comes into play. You have to have a feel for the language.
