i have a pen to write还是/write with

i have a pen to write还是/write with I use a pen to write.还是I use a pen to write with.为什么? I have no pen to write with I‘d like a pen to write 还是to write with 为什么 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 lost my pen.i have to write with a pencil Do you have a pen to write with? I didn't have a pen to write with so she gave____to me write with a pen I need a pen _______A.to write B.to write with C.writing D.w I need a pen to write 和 I need a pen to write with那句对?为什麽?