Take the words ‘dependant‘ and ‘dependent‘. This is one that many people confuse, and of course spell checker won’t tell you if you’ve used the wrong one as it will recognise both words as being spelled correctly.
But there’s a very clear difference that makes it easy to know which one to use.
Dependant is a noun and is someone who depends on, or looks to another for support.
Dependent is an adjective and means depending on something else for help or support.
I have four furry dependants (noun) and they are all dependent (adjective) on me.