reasons why
fixed phr..fixed phr.. A phrase you use to introduce the explanations or causes for something.
fixed phr.. A common collocation used to introduce a clause that provides the justification or explanation for a preceding statement.
There are many reasons why I moved here.
She explained the reasons why she couldn't attend the meeting tomorrow.
The inquiry sought to uncover the complex historical and social reasons why the community had become so deeply divided.
This phrase is followed by a clause that explains the 'reasons'.
Note that 'the reasons that' is a common alternative, and some style guides consider 'the reasons why' redundant, preferring just 'the reasons' or 'why'.
These are the reasons because I was late.These are the reasons why I was late.Use 'why' or 'that' to connect 'reasons' to its explanation, not 'because'.