I would like to write a formula that counts the number of times any one of multiple conditions appear in a column cell.

I know this notation is incorrect, but what I am trying to do is basically this:

=countif(a:a "ABC", "DEF", "GHI", "JKL")

...to count the number of times either ABC, DEF, GHI, or JKL appear in column A. What am I doing wrong in my notation, and how could I use an array formula to count these conditions?

Thank you very much, in advance, to anyone who can offer any help with this!