Is there any difference between the expressions different from, different than, and different to? Is one of the three ‘more correct’ than the others?
In practice, different from is by far the most common of the three, in both American and British English:
This part is totally different from anything else that he's done. (American English)
We want to demonstrate that this government is different from previous governments. (British English)
Different than is predominantly used in American English:
Teenagers certainly want to look different than their parents.
Because it can be followed by a clause, different than can be more concise than different from. For example:
Traffic patterns today are totally different than they used to be two decades ago.
Traffic patterns today are totally different from the way they used to be two decades ago.
Different to, although common in British English, is disliked by traditionalists and sounds strange to American ears:
In this respect the Royal Academy is no different to any other major museum.