Using 'much' without the adjective 'very' after "I love you"

The background to this question is a conversation with some people I know. One of which is a native American (southern U.S.), myself (native Swedish, fluent in English) and other various languages represented. The conversation made me realise that, in English, the sentence "I love you much" sounds weird (we all agreed), whereas "I love you very much" sounds perfectly fine.

Now, I'm not a linguist by any means, but to my knowledge the word 'much' in this case, is an adverb - as it modifies the verb to love. I don't know if 'very' is an adjective, or if there's a separate word class for words that modify other adverbs (or adjectives for that matter). I've been racking my brain trying to find another case where an adverb (much) can only be used in conjunction with another word (very), and can't find any. Is this merely a case of informal use, or am I missing some grammar rule I should've learned in school?

I put this under the grammar tag, since my example sentence is of less importance than the actual question of the grammar around it. I'm happy to be proven wrong or simply learn more, so don't hesitate to just throw it out there if I'm totally off track! Thanks in advance!

Solution 1:

The Cambridge Grammar of the English Language p772 has the following to say on this topic.

[Much] is subject to considerable restrictions. In end position [much] normally behaves as a non-affirmative item unless it is itself modified by a degree adverb: I don’t like it much, I like it very much, but not *I like it much. It can occur in central position in affirmative contexts with a limited range of verbs such as appreciate, enjoy, outrank, prefer, surpass, underestimate: I much appreciate your concern. In some cases, we find that unmodified affirmative much is permitted in passives but not in the corresponding active:

[11 ] i She had been much abused by her stepfather.

ii *Her stepfather had much abused her.

There are some historical examples to be found of much in end position with love.

I love you much, yet is my love as pure as the white snow this so resembles (The villain a tragedy / written by T. Porter, Esq.; 1663)

I love you much, but love my honour more (Love triumphant; John Dryden; 1694)

I hesitate not because I love my country little, but because I love you much, and much need you here. (The Death of Capt. Nathan Hale; Trumbull, David; 1845)

there was a growing party in the House and in the country which was disposed to say, " If you love us, give us an income tax; and if you love us much, make it perpetual (British Parliament; House of Commons; 1851_03_10)

O robin, you darling, I love you much; But there is another whose slightest touch And faintest whisper my heart can thrill (The select poems; English, Thomas Dunn; 1894)

And, in modern use, as an informal valediction.

Think about ways to sign your emails -- Love you much,' Thinking of you,' Thanks darling' -- to make your messages affectionate and warm instead of in a business context, " he says. (Canadian Living)

The final message was the soft drawl of her best friend, Suzanne, who still lived in Atlanta but called from a hotel room in Chicago, where she was helping to put on a large party for one of her corporate clients. " Enjoy your big three-oh, darling! Love you much! " The message was genuine, but the tone artificially perky. (The marriage pact : a novel; M J Pullen; 2016)

So, getting back to the original question, it would seem more a matter of idiom than a strict rule not to use much by itself as a degree modifier in end position with verbs such as love, like, etc.