Difference between Have a word with someone and Have words with someone

have a word with someone—have a short conversation with a person:

• The personnel manager said he wanted to have a word with me.

Note: The expression is not equivalent in meaning to the phrase have a word in someone’s ear—give a brief message to a person in confidence:

• My employer, the cadi, wants to have a word in your ear.

have words with someone—have a quarrel with smb.:

• Our cab arrived and the same man whom we had words with a few minutes earlier came out.