Copy the selected text

`⌘ Cmd` + `C`

All hotkeys for Apple Messages

Messages Open Messages preferences	`⌘ Cmd` + `,`
Messages Hide Messages	`⌘ Cmd` + `H`
Messages Hide everything except Messages	`⌥ Option` + `⌘ Cmd` + `H`
Messages Quit Messages	`⌘ Cmd` + `Q`
Messages Start a new message	`⌘ Cmd` + `N`
Messages Go to a chat room	`⌘ Cmd` + `R`
Messages Open the Messages window	`⌘ Cmd` + `0`
Messages Close the Messages window	`⌘ Cmd` + `W`
Messages Print the conversation	`⌘ Cmd` + `P`
Messages Search all conversations for matching text	`⌘ Cmd` + `F`
Messages Clear the transcript (delete a conversation without closing it)	`⌥ Option` + `⌘ Cmd` + `K`
Messages Open the Emoji & Symbols window	`Control` + `⌘ Cmd` + `Space`
Messages Minimize a window	`⌘ Cmd` + `M`
Messages Minimize all windows	`⌥ Option` + `⌘ Cmd` + `M`
Messages Open the buddy list window	`⌘ Cmd` + `1`
Messages Open the File Transfers window	`⌥ Option` + `⌘ Cmd` + `L`
Messages Enter full-screen view	`Control` + `⌘ Cmd` + `F`
Messages Set your status to Offline in the buddy list	`Control` + `⌘ Cmd` + `O`
Messages Set your status to Invisible in the buddy list	`Control` + `⌘ Cmd` + `I`
Messages Set your status to Available in the buddy list	`Control` + `⌘ Cmd` + `A`
Messages Set your status to Away in the buddy list	`Control` + `⌘ Cmd` + `W`
Conversation shortcuts Make the text bigger	`⌘ Cmd` + `+`
Conversation shortcuts Make the text smaller	`⌘ Cmd` + `-`
Conversation shortcuts Insert a line break (in a message)	`⌥ Option` + `⤶ Enter`
Conversation shortcuts Copy the selected text	`⌘ Cmd` + `C`
Conversation shortcuts Paste copied text	`⌘ Cmd` + `V`
Conversation shortcuts Open the Spelling and Grammar window	`↑ Shift` + `⌘ Cmd` + `:`
Conversation shortcuts Check the text field for spelling and grammar issues	`⌘ Cmd` + `;`
Conversation shortcuts Select the next conversation	`Control` + `⭾ Tab`
Conversation shortcuts Select the previous conversation	`Control` + `↑ Shift` + `⭾ Tab`
Conversation shortcuts Send an email to a selected person in the conversation	`⌥ Option` + `⌘ Cmd` + `E`
Conversation shortcuts Show video effects (while in a video call in Messages)	`↑ Shift` + `⌘ Cmd` + `E`
Conversation shortcuts (first, select the message) Delete a single message	`Del`
Conversation shortcuts Close all conversations	`⌥ Option` + `↑ Shift` + `⌘ Cmd` + `W`