Oh brother vs Oh no vs Really

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

Oh brother

InformalBeyond 10,000 (less common)

Oh no

InformalTop 1,000 (very common)

Really

Top 1,000 (very common)A1adverb
Most formal: Really
 Oh brotherOh noReally
Pronunciation🇬🇧 //əʊ ˈbrʌðə//🇺🇸 //oʊ ˈbrʌðər//🇬🇧 //əʊ nəʊ//🇺🇸 //oʊ noʊ//🇬🇧 /["/ˈriːəli//ˈrɪəli/"]/🇺🇸 /["/ˈriːəli/"]/
MeaningA way to express frustration or annoyance about something.An expression of surprise or disappointment.very or truly
ExampleOh brother, I can't believe I forgot my keys again!Oh no, I left my phone at home!I really enjoy going to the beach.
RegisterInformalInformalNeutral
How commonBeyond 10,000 (less common)Top 1,000 (very common)Top 1,000 (very common)
CEFR level--A1
Part of speechadverb
Collocationsoh brother, not again, oh brother, seriously, oh brother, come onoh no moment, say oh no, express oh noreally want, really good, really sure, really excited, really important
Antonyms-Oh yes, Hooray, Great, Fantasticseldom, never
Common mistakesUsed as a greeting instead of an expression of frustration., Mispronounced as two separate words instead of a chunk., Used in overly formal contexts.Saying 'oh no' too loudly in quiet settings., Using it when you mean to express happiness.Using it in place of 'real' when describing a noun., Confusing it with 'really' in terms of degree, e.g., 'really good' instead of 'very good'.
Usage notesUsed when surprised or exasperated by a situation. It's often casual and used among friends or family, but can be seen as unprofessional in formal settings.Used in casual situations to express dismay. Avoid in formal contexts.Used to emphasize an adjective or another adverb. It can be informal in casual conversations but is accepted in most contexts; avoid overusing it in formal writing.

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Oh brother
Oh no
Really

Frequently asked questions: Oh brother vs Oh no vs Really

What's the difference between Oh brother, Oh no, and Really?

Oh brother: A way to express frustration or annoyance about something. Oh no: An expression of surprise or disappointment. Really: very or truly

Which is more formal: Oh brother, Oh no, and Really?

Really is the most formal of these.

Can you show an example of each?

Oh brother: Oh brother, I can't believe I forgot my keys again! Oh no: Oh no, I left my phone at home! Really: I really enjoy going to the beach.

Can I use Oh brother, Oh no, and Really interchangeably?

Not always. Oh brother, Oh no, and Really 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.