Incomplete “able to” in next sentence

Question

Consider the following two sentences (from this SO answer):

So the fact that you can now reference pygame.display is an accident of implementation details. You may not be able to in future versions (if the project no longer needs to import pygame.display to load pygame.joystick, for example).

The sentence "You may not be able to in future versions" seems incomplete to me. I think it is missing something and "You may not be able to do it in future versions" will be more complete. So, my question, is the first form without do it correct and complete?

Answer 1

Yes, it is correct and complete. You may omit the verb phrase when its meaning can be understood from the context. In linguistics, this phenomenon is known as ellipsis. In your example:

So the fact that you can now reference pygame.display is an accident of implementation details. You may not be able to [reference pygame.display] in future versions.

One could also say

You may not be able to do that in future versions.

Other examples of verb phrase ellipsis:

A: Do you want me to go with you?

B: Oh, you don’t have to [go with me].

or

He says that I should become an astronaut, but I don’t want to [become an astronaut].

Here’s a similar question — Omitting verbs, is it correct?