"There is a banana and an apple on the floor."
"There are a banana and an apple on the floor."
"There are bananas and an apple on the floor."
"There is a banana and apples on the floor."
I'm confused with the rules of using "is" and "are." Please tell me which one is correct and which is not.
And based on what the verb has to be conjugated? Is it the total amount of the subject mentioned or is it just the first subject?