Answer:
I have a spelling checker
It came with my PC
It plainly marks for my review
Mistakes I cannot see
I strike a key and type a word
And wait for it to say
Whether I am wrong or right
It shows me straight away
As soon as a mistake is made
It knows before too long
And I can put the error right
Its rarely ever wrong
I have run this poem through it
I am sure you're pleased to know
Its letter perfect all the way
My checker told me so
Step-by-step explanation: