Have you ever been frustrated on a Mac because switching input between Japanese and English with “Command+Space” does not go smoothly due to a delay?
For people using the latest Macs this may not be something worth worrying about, but I still use an iMac 2009, so the dialog that appears in the center of the screen tends to take control, and especially when I am working in the terminal or writing an article and switching frequently, sometimes it does not switch the way I want it to.
As shown in the figure below, the slowness seems to be caused by what appears in the center of the screen when switching. As a result, input mode changes increasingly ended up misfiring, and it became extremely stressful.

Changing the “Command+Space” setting
Swap the assignments in “System Preferences > Keyboard > Shortcuts > Input Sources” the other way around.

Specifically, select the setting item so that it is highlighted in blue, then click the keyboard shortcut part.
- Click the “⌘Space” part and press
Command+Option+Space. - Click the “⌘⌥Space” part and press
Command+Space.
That reverses the assignments.

From then on, pressing Command+Space makes the display in the center of the screen go away, and the input mode switches instantly.
If you find it hard to notice, you can confirm the switch by looking at the input switching icon in the top right.
With this, input switching became fast and comfortable even on my slow iMac.
I should have done this much sooner.
Let’s add it to the list of things to do first thing after buying a Mac!