To think that one person or thing is another, usually by mistake.
I always mix up their names because they look so similar.
A: Did you call Sarah? B: Oops, I mixed up her number with Emma's and called the wrong person.
Sometimes I mix up the dates for my appointments, especially when I'm busy.
Common mistake
✗I always mix up them.
✓I always mix them up.
With a pronoun, the object goes in the middle: 'mix them up'.
Tell it apart
I always mix up their names.
confuse one for the other
I always mix up a smoothie.
combine ingredients
Use 'mix up' when you accidentally confuse two people or things, not when you are physically combining them.'Mix up' here means to confuse, not to physically combine things together.
To put different things together so they are mixed or combined.
Mix up the ingredients before you pour them into the pan.
A: How do you make this salad? B: Just mix up all the vegetables and add some dressing.
When I cook, I like to mix up different spices to create new flavors.
Common mistake
✗Mix up well the batter.
✓Mix the batter up well. / Mix up the batter well.
Keep the adverb at the end: 'mix it up well'.
Tell it apart
Mix up the salad before serving.
combine / toss together
Don't mix up the twins.
confuse one for the other
Use 'mix up' when you are combining things, especially if it's done quickly or without much care.'Mix up' here is about physically combining things, not confusing them.
To make a situation, issue, or discussion more confusing or complicated, often unintentionally.
Bringing up unrelated topics will only mix up the discussion and make it harder to reach a conclusion.
A: Do you think adding more rules will help clarify things? B: Honestly, it might just mix up the whole process even more.
Introducing conflicting data at this stage could mix up the debate and distract from the main point.
Common mistake
✗Don't mix up the things more.
✓Don't mix things up even more.
It's separable — 'mix things up'; 'even more' reads more naturally than 'the things more'.
Tell it apart
Now you've mixed everything up.
thrown it into confusion
Now you've cleared everything up.
resolved the confusion
'Mix up' in this sense is used to talk about making a problem, discussion, or situation more confusing, not about confusing two specific things or physically combining them. It is common in spoken and written argument or analysis.Unlike the B1 senses, which refer to confusing two things or physically combining them, this sense is abstract and evaluative, focusing on making a situation or issue more confusing overall.