1. To combine with something else. Make sure to continue stirring the egg whites vigorously and steadily so that the sugar mixes in evenly. I love barbecuing in the summer, as the smell of sizzling hamburgers and sausages mixes in with the aromas of the lush, sunsoaked grass and trees.

2. To combine or mingle something with something else. In this usage, a noun or pronoun is used between "mix" and "in." This turbine mixes a powerful cleaning agent in with the contaminated water to kill any bacteria present. Mix the salt in very slowly and steadily, or else it won't dissolve into the solution properly.

3. To converse or chat (with someone or a group of people) in an easy, friendly manner; to mingle or fit in well (with someone or a group of people). I've got to talk to Mike for a while about a work issue, so why don't you go and mix in with some of the other people at the party, and I'll join you in a minute. I was worried that Tommy wouldn't like starting play school, but it's great to see him mixing in right away.

4. To join or mingle two or more people in a social situation. In this usage, a noun or pronoun is used between "mix" and "in." I always find it awkward trying to mix my regular friends in with co-workers on a night out. I want to mix my son in with some more kids his age.