Suggestions for Regex QA check: Verb "click" must be followed by preposition "on"


Disclaimer: I'm a beginner where Regex is concerned, so apologies if this is a silly question!

I'd like to set up a Regex QA check to flag up target segments where I've forgotten to use the preposition "on" after the verb "click".

The best I've come up with is to enter Click [^o] in the RegEx target box, with "Report if target matches (target check only)" as the condition. But obviously this is case sensitive and doesn't cover "clicks", "clicking", "clicked".

Does anyone have any suggestions for a more "comprehensive" rule that would save me entering all the different variants (click, Click, CLICK, clicking, Clicking, CLICKING and so on and so on...!)?