Be nice vs You be good

When to use each in English, with meaning, register, and examples.

Be nice

Top 5,000 (fairly common)

You be good

InformalTop 5,000 (fairly common)
Most formal: Be nice
 Be niceYou be good
Pronunciation🇬🇧 //biː naɪs//🇺🇸 //bi naɪs//🇬🇧 //juː biː ɡʊd//🇺🇸 //ju bi ɡʊd//
MeaningTreat others kindly.A way to tell someone to behave well.
ExampleYou should really try to be nice to your classmates.As the kids left for school, she reminded them, 'You be good!'
RegisterNeutralInformal
How commonTop 5,000 (fairly common)Top 5,000 (fairly common)
Collocationsbe nice to, be nice for, be nice in, try to be nice, always be niceYou be good to others, You be good at school, You be good for me
Common mistakesUsing 'be nice' in serious discussions may seem insincere., Confusing 'be nice' with 'be polite'; they are similar but not identical., Overusing 'be nice' in advice can make it sound generic.Confusing with 'You do good' which is more about doing well in tasks., Using in overly formal situations where politeness would be more appropriate.
Usage notesUsually used as a suggestion or reminder. It's friendly and positive, ideal for casual conversations but can also work in formal contexts.Commonly used by parents or guardians when addressing children. Avoid using in formal contexts.

See it in real clips

Be nice
You be good

Frequently asked questions: Be nice vs You be good

What's the difference between Be nice and You be good?

Be nice: Treat others kindly. You be good: A way to tell someone to behave well.

Which is more formal: Be nice and You be good?

Be nice is the most formal of these.

Can you show an example of each?

Be nice: You should really try to be nice to your classmates. You be good: As the kids left for school, she reminded them, 'You be good!'

Can I use Be nice and You be good interchangeably?

Not always. Be nice and You be good are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.