It's all about correct punctuation

So a few days ago, my English teacher was teaching us English. (obviously)

She gave us this sentence to correct;

You write a pen.

I corrected it like

You write, "a pen".

Now, I expected at least three different answers, like

You! Write "a pen"! (Imperative sentence)

but everyone except me wrote

You write with a pen.

And I thought, 

"Wow. The power of Korean schools. Where they kill your creativity so mercilessly that you don't have any variation in correcting a sentence."

Honestly. This is just crazy.