Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

I don't get anymore wetter, no matter how much rain falls on me.

What month of the year has 28 days?

I am dry when I go inside, but wet when I am pulled outside.
The longer I am inside, the stronger I get
When I am completely out, I am wet and I literally sag
Who am I?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

John was piloting a plane behind a car but was never able to overtake it. Why?

I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?