"take note of..", "take a note of..", "take notes of" are different meaning? If so, what do they mean each? I can't figure them out only by looking up the dictionary.
"take note of" is a set idiomatic expression meaning to notice or pay attention to (something). e. g.
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"take note of" is a set idiomatic expression meaning to notice or pay attention to (something).
"take a note of" can be used in the same way (though to me the more standard expression is without "a"), or it can be used literally, i.e. meaning to write down a note e.g. in a notebook.
"take notes of" is only used literally.