Tap and drag with trackpad and FN keys in macOS Sierra (10.12.5)
Tap and drag with trackpadIf you’re accustomed to tapping and then moving Windows in Linux distributions or Windows, you can enable tap and drag on a macOS system from System Preferences > Accessibility.
1. In System Preferences, click Accessibility > Mouse & Trackpad > Trackpad Options.
2. Select Enable dragging. If needed, select with drag lock or three finger drag from the option list.
3. Click OK.
FN key option
On the MacBook Air, the FN keys follow hardware functions such as Brightness up, Brightness down, and volume controls by default. If you prefer the FN keys to perform desktop application-defined FN functions, change the keyboard settings.
1. In System Preferences, tap Keyboard.
2. Select the Use F1, F2, etc. keys as standard function keys option.