how i use were with I

it happens in conditional type sentences like - i wish if eg I wish i were the pm i wish i were a cricketer i wish i were a singer and if i were the pm the coumtry would grow if he were there i would not go

We use "were" with "I" in imaginary if conditions... Ex... If I were a bird, I would fly all over the earth. If I were the PM, I would make this country corrupt-free. If I were you, I would help you out...etc.