There are lots of words that are similar in their meaning or their spelling—or both—and leave otherwise erudite authors in a puddle of verbal phobia. Let’s look at a few. Averse: Disinclined, reluctant, loath Adverse: Opposed, hostile, antagonistic Advice: (a noun) A recommendation regarding a decision or course of conduct Advise: (a verb) To give advice Discrete: Constituting a separate entity; individually distinct Discreet: Having or showing discernment or good judgement in conduct and especially in speech Farther: (comparative) At or to a greater distance or more advanced point. Use farther to describe physical distance. Further: (comparative) In addition, to a greater degree or extent. Use further to describe non-physical distance (“the book delved further into the topic”). Lay (transitive): To put or set down—in motion. The past tense is laid, the present participle (gerund) is laying, the past participle is laid. Lie (intransitive): To be or to stay at rest in a horizontal position. The past tense is lay, the present participle (gerund) is lying, the past participle is lain. Less: (comparative) Constituting a limited number. Use less if the compared term cannot reasonably be counted, like water or sand. Fewer: (comparative) A smaller number of limited things. Use fewer if the compared term can be counted, like applications or tortilla chips. Lets: Allows. Lets is more casual than allows but means the same thing. (The hole under the fence lets the dog clamber through.) Let’s: A contraction for “let us.” Use let’s if you’re about to invite your reader to do a task. Log in/log on (verb): To enter personal data and get into a program. (The user must log in using the dialog box.) Login/logon (noun): Pre-programmed access to an application or program. (The login program ran automatically when the application executed.) Raise (transitive): To cause or help to rise, an act of standing or lifting Rise (intransitive): To assume an upright position, to ascend Set up (verb and preposition): To create an organization of something. (He set up the computer to his own specifications.) Setup (noun): The commencement aspect of a program or application. (He initiated the setup wizard.) Set (transitive): To transfer action to an object, to place an object down on a surface Sit (intransitive): To occupy a place or a chair That: Used for a defining clause (the building that burned) to refer to persons or things Which: Used for a non-defining clause, almost always with a preceding comma (the building, which burned, was on my block), to refer to things. Their: Possessive. Something that belongs to them. There: In or at a certain place They’re: Contraction for they are. (They’re taking their dog over there.) Use (verb): The act or practice of employing something, to put into action or service. (I use the elevator.) Utilize (transitive verb): To actively make use of something. (I utilize the elevator to get to my office.) Has a slightly positive connotation. Your: Possessive. Something that belongs to you. (The box belongs to your sister.) You’re: Contraction for you are. (You’re going to visit your sister.) These definitions came partly from Webster’s Dictionary and partly from Theodore M. Bernstein’s The Careful Writer. Examples are mine alone.