• We use which when we have limited options, not wide.
• Example: Which color do you prefer – green or white? It doesn’t have to be only
  two, it could be three, four, or 10, but it’s limited and not unlimited. 

Let’s look at a few more examples so you can understand exactly how this works.

Here are some examples in three different contexts:

1. Social
What do you want to do on holiday? (very broad, very general)
Which sport do you want to do on holiday – kayaking or cycling? (the choice is much more limited, specific)

2. Academic
What would you like to learn? (out of all the subjects in the world)
Which school subject do you choose – English or Spanish? (the choice is very limited)

3. Business
What are our options? (out of all the different things we could do)
Which country do you prefer to cooperate with – the USA or Germany? (a much more limited choice)