as an adjective, 'real' primarily describes something that exists or occurs as a fact; something that is genuine rather than imaginary or fake.
'real' can be used to differentiate between fact and fiction. It can describe the authenticity of an item or emotion. 'Real' can also emphasize the fundamental nature of something.
This is a real diamond, not a fake one.
Her happiness was real and palpable.
The real issue is not what he said, but why he said it.
avoid using 'real' before gradable adjectives like 'happy' or 'sad.' Instead, use 'really.' 'Real' can sometimes be used colloquially in place of 'really' before adjectives, especially in American English, e.g., 'That movie was real good!' However, this is considered informal.
as an adverb, 'real' is informal and is used to emphasize an adjective or another adverb, similar to 'very' or 'really.'
'real' can intensify the meaning of an adjective or another adverb. It's commonly used in informal speech, especially in certain dialects of American English.
It's real cold outside.
She runs real fast for her age.
in formal writing or speech, it's preferable to use 'really' instead of 'real' as an adverb. 'Real' as an adverb is more accepted in American English than in British English.