Write is a verb meaning to form letters, words, or symbols on a surface, typically with a pen or pencil. For example:
* I write letters to my grandmother every week.
* Please write your name on the line.
Wright is a noun meaning a person who makes or works with something, often using their hands. It is often found in compound words like:
* Blacksmith (a person who works with iron)
* Wheelwright (a person who makes or repairs wheels)
* Playwright (a person who writes plays)
So, to answer your question, you don't need a dictionary to tell the difference. They are spelled differently and have different meanings.