Your is possessive: “Your notebook is on the chair.” You’re is a contraction of “you are”: “You’re ready to begin.” If the sentence still works when you’re becomes you are, keep the contraction; if it refers to something belonging or relating to you, use your. [1]
One word shows a relationship; the other makes a statement
Your comes before a noun or noun phrase to connect it with the person being addressed: your question, your voice, your place in the queue. It does not mean that the item must be owned in a legal sense; it can mark association or relevance. “Your turn” means the turn assigned to you.
You’re contains a subject and a verb: you plus are. It can describe a state (“You’re quiet”), an ongoing action (“You’re reading”), or a passive verb phrase (“You’re invited”). Purdue OWL identifies your as possessive and you’re as a contraction of you are. [1]
Run the expansion check
When you see you’re, expand it to “you are.” “You’re carrying the lantern” becomes “You are carrying the lantern,” so the contraction works. “I saved you’re place” becomes “I saved you are place,” which does not work; the sentence needs “your place.”
The reverse question is helpful for your: does it point to something associated with you? In “Your explanation changed the discussion,” your identifies whose explanation. If you mean “you are explanation,” the sentence makes no sense. Replacing the word is a quick check, but first be clear about the sentence’s intended meaning.
A small example to edit
Suppose a workshop reminder reads: “Your joining us at six, and you’re seat is near the door.” If the writer means a person will join at six, revise the first phrase to “You’re joining us at six.” If the seat is assigned to that person, revise the second to “your seat.” The corrected note is: “You’re joining us at six, and your seat is near the door.”
Now compare a different meaning: “Your joining us at six would help.” Here, your comes before joining, an -ing form functioning as a noun phrase: the sentence means that the person’s joining would help. This is not a typo for you’re joining. Purdue OWL describes gerunds as -ing forms that can function as nouns, including as sentence subjects. [2]
Do not confuse possession with identity
A common error comes from expecting an apostrophe wherever a word signals possession. But your is a possessive pronoun form, like my, his, hers, and ours; it does not take an apostrophe. The apostrophe in you’re marks letters omitted from you are. Purdue OWL’s apostrophe guidance distinguishes possessive pronouns from contractions and advises against adding apostrophes to possessive pronouns. [3]
That explains why “your welcome” is usually wrong when intended as a response to thanks: the intended phrase is “you are welcome,” or you’re welcome. But “your welcome note” is correct if welcome describes a note associated with you. The surrounding words determine which grammatical job is needed.
Proofread by asking two questions
On a final pass, scan each your and you’re. First, can you expand you’re to you are without changing the intended meaning? If yes, it is likely correct. If no, ask whether your connects you to a noun or noun phrase. “Your draft,” “your speaking,” and “your reply” can all use your because the next expression functions as the thing or activity associated with you.
Read the full sentence afterward. A sentence can pass the spelling check and still be unclear about who is doing what. For example, “Your speaking during the introduction surprised me” means the act of your speaking surprised the writer; “You’re speaking during the introduction” says that you are speaking then. The apostrophe changes the structure and the message.
