I have bumped into just A LOT of English native speakers saying: " the reason I need to buy a flight ticket right now is because I have to get back to the office tomorrow morning" ( a tourist at a travel agency)
"The reason I want to go to Peru is because you can eat one of the best CEVICHES ever" (ceviche is raw fish cut into small pieces and flavored with lemon ).
I have so frecuently heard "the reason I...is because I ..." that I have always assumed it is the right way to say. But to my great surprise , a beautiful Irish woman told me that saying" The reason I ... is because I... " is redundant.
According to her " the reason I bought this T-shirt is I need to play football tomorrow" Or " the reason I am here is I wanted to see you" are correct sentences.
As she is Irish, I guess it must be true. I'm wondering whether it's just about formal and informal ways of saying the same thing,or it's a real mistake.
Can someone make this clear to me?