The truth about "truely": a common spelling mistake explained

What kind of error is it?

Spelling error

Why do people make this mistake?

People may mistakenly believe "truly" follows the regular pattern of forming adverbs by adding "-ly" to an adjective. Since "true" ends with "e", they might think they need to keep the "e".

What is correct?

"Truly" is the correct spelling of the adverb form of "true". The "-e" is dropped before adding "-ly".