`\linebreak[number]`
The `\linebreak` command tells LaTeX to break the current line at the point of the command. With the optional argument, `number`, you can convert the `\linebreak` command from a demand to a request. The number must be a number from 0 to 4. The higher the number, the more insistent the request is.
The `\linebreak` command causes LaTeX to stretch the line so it extends to the right margin.