Tom still hasn't told me the reason why he isn't going to do that. - Tom still hasn't told me the reason why he's not going to do that.
Why did he come here? - What is the reason why he came here?
the real reason
Hyphenation
the re·al rea·son
Turkish pronunciation
dhi ril rizın
Pronunciation
/ᴛʜē ˈrēl ˈrēzən/ /ðiː ˈriːl ˈriːzən/
Etymology
[ before consonants usually ] (definite article.) before 12th century. Middle English, from Old English thE, masc. demonstrative pronoun & definite article, alteration of sE; akin to Greek ho, masculine demonstrative pronoun & definite article; more at THAT.