"Until" is a word that has several uses in the English language, primarily related to time and condition. Here are some of the common uses:
1. Time: It indicates a point in time up to which something happens.
"I'll wait until you're ready."
"We can't leave until the rain stops."
2. Condition: It is used to express that something will continue to be true until a certain condition is met.
"I won't go to the party until I hear from you."
"You can borrow the book until you finish your project."
3. Negation: It can be used to express that something is not true or not happening until a certain point.
"I haven't seen him until now."
"She didn't speak until the teacher called on her."
4. Comparison: It can be used to compare two things, indicating that one will continue until the other is reached or surpassed.
"He ran until he couldn't run any more."
"The price of the stock will continue to rise until it reaches $100."
5. Conjunction: It can act as a conjunction, connecting two clauses or sentences.
"I'll help you until I can't anymore."
"She was happy until she heard the news."
"Until" is also used in various idiomatic expressions and phrases, such as "until further notice," "until the cows come home," and "until the end of time."
