A is to B is what C is to D or A is to B as C is to D? [closed]
I've seen both 'what' and 'as' interchangeably used in many sentences the latter being more common. I want to know which usage is grammatically correct.
Grammatically, the second one is correct. A is to B as C is to D.
But the same can be conveyed by using 'what'. This is how: A is to B is what C is to D. With the missing is before 'what', the sentence is incorrect.
The completeness of the sentence is the key to understand such differences. I hope this helps.