Set how quickly a key repeats
If you press and hold certain keyboard keys when in a text area, the key’s character begins to repeat. For example, the Delete key continues to remove text for as long as you hold it down.
You can set how long you must hold down the key before it starts repeating and how fast it repeats once it starts.
Choose Apple menu > System Preferences, click Keyboard, then click Keyboard.
Drag the Delay Until Repeat slider to set how long to wait before the character begins repeating.
Drag the Key Repeat slider to set how fast characters repeat.
You can add accent marks and special characters to some letters. For example, click and hold the a key to type à, á, â, or other characters.
If you set the Key Repeat slider to Off, special characters won’t appear when you hold down a key.