i have no pen to write with.像这类的题.怎样才能知道要加with?有什么技巧吗

I have no pen to write with I have a pen to write with.后边为什么要加个with?有什么规律? （I have a pen to write with）句中 为什么加 with i have a pen to write还是/write with I have no pencil to write with Do you have any pens?I need a pen to write _______ 我知道要用with The pen is good to write为什么要加with The pen is good to write(要加介词with吗?) i write a letter with pen是对的吗? i lost my pen.i have to write with a pencil Could you lend me a pen to write with?为什么要加with I want to borrow a pen ____ to write with 为什么要用with