What does the "s" in "thanks" mean?

Question

I'm teaching English in a non-English-speaking country where plural "s" and third-person "s" get confused a lot with no "s" at all. The dialogue in the textbook was explaining how you should respond when someone compliments you:

Mike: For example, when you have a new bag, I can say, "I like your bag."
Yuki: What should I say then?
Mike: You should say, "Thanks."
Yuki: Should I say anything else?
Mike: No. Just "Thanks."

I was asked what the "s" in "Thanks" means, but I couldn't give a straight answer. I know in the phrase "give thanks" it's a plural noun, but what about when it's used as an interjection? Why does it go from "Thank you" to "Thanks"?

Answer 1

You're right that "thanks" is always used as a plural noun, whereas when we say "thank you," the word "thank" is a verb.

You can explain that some nouns are always used in their plural form, and give other examples (clothes, outskirts, glasses, scissors, etc.).

You could alternatively tell your students each expression of thanks is a shortened form of a longer sentence that isn't really in use anymore.

(I) thank you. -- Thank you.

Thanks (be to you). -- Thanks.

or

(I give/feel) thanks. -- Thanks.

Answer 2

My interpretation is that my is elided.

[My] thanks!

A longer interpretation would be:

[I give you my] thanks!

You could also say that it's imperative:

[Take/receive my] thanks!

Thanks is one of many responses we use when time is short or a longer expression seems egregious or pretentious. In a similar vein, we respond to good news with congratulations! an unintended slight with apologies! or sad news with condolences.

Answer 3

It is a plural.

You could say 'Many thanks'

The confusion is that it is not really used as a single noun.

Answer 4

Thanks should have the same logic as Gracias in Spanish or Grazie in Italian, all of them are plural nouns. When we say Gracias in Spanish we mean Yo te doy gracias, i.e., I give you thanks.