What are patterns?
People love patterns in interfaces. Web design patterns such as breadcrumbs, dropdown menus, a shopping cart, and modals allow users to complete tasks much faster and more efficiently. The best thing about patterns is that users know what to expect from them and how to use them.
From the point of view of a UX designer, they are a set of guidelines for creating a specific design element or component. In UX writing, patterns are templates or best practices for writing copy for the most common components and elements. For example, buttons usually use imperative verbs to define an action, and a navigational menu can have nouns and verbs for labels, while adjectives are relatively rare.
Keep in mind that like web design patterns, UX writing patterns aren't universal, may not work for specific products, and always require testing with your audience. A subtle change in word choice can be a whole different ball game for user experience. For example, the button label "Join Us" is technically correct, but it may be somewhat confusing for users and make them wonder what happens after they click the button — do they subscribe to a newsletter, join a product's community, or simply sign up?