This post describes steps one can take to turn on or off single or one click to open an item in Ubuntu Linux.
By default, it takes double clicks to open an item in File Manager in Ubuntu Linux. The double clicks feature is meant to prevent accidental open of items when opening files and folders.
Not everyone is able to double-click or do it properly. You can instead choose to have files and folders open when you click on them once. When you use single-click mode, you can hold down the CTRL key while clicking to select one or more files.
Ubuntu Linux allows that, too.
When you turn on single click in File Manager preferences, users will be able to open files and folders simply by clicking on them without the need to double click.
Below is how to do that in Ubuntu Linux.
How to turn on or off single-click to open an item on Ubuntu Linux
As mentioned above, Ubuntu Linux by default allows double clicks to open files and folders. However, users who are not able to use the double clicks feature can turn on single click.
To change to a single click, open File Manager in Ubuntu Linux and go to Options -> Preferences.
On the Preferences window, under General, select Action to Open Items option and change the click mode.
To change back to Double click, choose that instead.

The changes should apply immediately after changing the click mode.
That should do it!
Conclusion:
This post showed you how to turn on or off single click mode in Ubuntu Linux. If you find any error above or have something to add, please use the comment form below.