Correct spelling, explanation: barely is an English word with a long history as it already appeared in Old English, in which it had the form bærlice, which used to mean clear or public. Later, the meaning evolved and in Middle English, it also meant exclusively. In modern English barely also functions as an adverb, but its meaning has changed.

Definition of barely:
1. adverb – refers to a really small amount of something, hardly;
The sun is shining straight into my eyes so I can barely see the road.

Collocations with barely:
Some common collocations include: barely visible, barely ever, and barely there.
Don’t worry, the stain on your blouse is barely visible – no one will notice it.
We used to be close friends, but now we barely ever see each other.
I had a barely-there feeling that somebody was following me.

Incorrect spelling, explanation: English words bear and bare are so-called homophones, which means that their pronunciation is the same, but their spelling and meaning are different. As a result both learners and native speakers of English mix the words and that also influences the spelling of a popular adverb barely. A common mistake is to spell the word barely as bearly, which is wrong.