If you are asking this question, you have probably typed text then spaces in an attempt to make columns. This will only work if you use a "fixed-width" font (e.g., Courier). This method is not advised, and you are likely to have other problems, especially if you try to change the page margins. If you are trying to make a table, then use the Table command (see How do I create a table?). If you don't want a table, setting tabs may work (see How do I set tabs?).