Words perceived as opposites/antonyms that aren't.

[Space60]

Well, up/down, on/off, in/out, right/left and top/bottom are obvious opposites/antonyms. But certain words are often perceived as antonyms that aren't really antonyms.

Ask a child what the opposite of "dog" is and they will likely answer "cat". Ask them what the opposite of "salt" is and they will likely answer "pepper" or maybe "sugar".

"Dog" and "cat" aren't really opposites/antonyms just words for different mammals. But they are often perceived as such.

[linguistcat]

Vanilla and chocolate.

[Vijay]

Shirt(s) and pants?

[Ryan of Tinellb]

As a kid, I once made scrambled eggs with the idea that salt and pepper were opposites. It did not end well.

[zompist]

maybe...

sun and moon

think and feel

city and country

electron and proton (or nucleus?)

elf and dwarf

There's also the video game triad of electricity, fire, and ice.

[DesEsseintes]

CBB and ZBB

[Moose-tache]

So these are complementary sets. In English we don't really have a natural-sounding common word for members of a complementary pair, other than "mate" perhaps. So we extend the word "opposite" to include these cases. But that's not an insight into any of these concepts, nor is it even an insight into English semantics. It's just the result of English lacking one specific word to describe itself.

Imagine a language that lacks a common word for "result," and instead extends the word "end" to describe results. In that universe, there would be a ZBB thread that goes like this:

"Hey guys, can you think of any ends that aren't really at the end? I'll go first: being happy about your day going well, even though the day isn't over. That's an 'end' alright, but it's not at the end!"

Meanwhile in another universe, the language of the ZBB stretches the word "purpose" to cover "reason:"

"Hey guys, isn't it weird that we say 'The purpose of the sky being blue is Rayleigh Scattering,' when the sky is inanimate and doesn't have any sense of purpose? How strange!"

[Space60]

Hand and foot

Finger and toe

Arm and leg

Eat and drink

Fire and water/Fire and ice

Car and truck

Rain and snow

Animal and plant

Animal and person/human (in neither the scientific nor the colloquial meaning of the word "animal" are these words opposites.)

Meat and vegetables

Door and window

Spoon and fork

Chair and table

"Man" and "woman" aren't really opposites either nor any other gender contrasting words. The opposite of "man" is "boy" and the opposite of "woman" is "girl".

"Love" and "hate" aren't actually opposites though usually taken as such, just complementary emotions. The opposite of both is "indifference".

[Space60]

So these are complementary sets. In English we don't really have a natural-sounding common word for members of a complementary pair, other than "mate" perhaps. So we extend the word "opposite" to include these cases. But that's not an insight into any of these concepts, nor is it even an insight into English semantics. It's just the result of English lacking one specific word to describe itself.

Imagine a language that lacks a common word for "result," and instead extends the word "end" to describe results. In that universe, there would be a ZBB thread that goes like this:

"Hey guys, can you think of any ends that aren't really at the end? I'll go first: being happy about your day going well, even though the day isn't over. That's an 'end' alright, but it's not at the end!"

Meanwhile in another universe, the language of the ZBB stretches the word "purpose" to cover "reason:"

"Hey guys, isn't it weird that we say 'The purpose of the sky being blue is Rayleigh Scattering,' when the sky is inanimate and doesn't have any sense of purpose? How strange!"

Yes, this is what I was mainly curious about. As to why those sets were commonly perceived as opposites.

[mèþru]

Yes, this is what I was mainly curious about. As to why those sets were commonly perceived as opposites.

I think it is an example of radial categories at work regarding the definition of "opposite" in English. BTW, for me at least, antonym is a narrower, more technical term that excludes these pseudo-opposites.

[Tropylium]

So these are complementary sets. In English we don't really have a natural-sounding common word for members of a complementary pair, other than "mate" perhaps.

Conjugate.

Ask a child what the opposite of "dog" is and they will likely answer "cat".

Horse/cow, also. Perhaps goat/sheep?

[Hominid]

Deciduous and coniferous. One means that a plant loses its leaves regularly, and the other just means it's part of a taxonomic group characterized by the production of cones. The actual antonym of deciduous is "evergreen."

[Ryan of Tinellb]

Deciduous and coniferous. One means that a plant loses its leaves regularly, and the other just means it's part of a taxonomic group characterized by the production of cones. The actual antonym of deciduous is "evergreen."

Dromedary and Bactrian. Until we engineer an n+1-humped camel.
Actually, though, I don't think I've used coniferous as an antonym, but that's probably localisation. We have a higher proportion of non-pine-esque non-deciduous trees here in Australia.

[Tropylium]

"Broad-leaved (tree)" makes IMO a better conjugate for "conifer", seeing how these do not overlap; "deciduous" does, viz. larches. But I get the feeling this is not really thought of as a single concept in English. (Finnish has the somewhat succinct lehtipuu 'leaf tree' versus havupuu 'conifer'.)

[Kuchigakatai]

Colombian Spanish: sopa y seco 'soup and dry (food)'. Refers to soup accompanied by meat and/or rice in a separate plate.

Ancient Chinese: mountains and rivers (山川, 江山).

Ancient Chinese: the gods of earth and the gods of grain, or their respective altars (社稷).

Chinese: firewood and water (薪水, which together mean the "salary" for one's work).

In El Salvador, Catholics and "Evangelicals" (actually Protestants).

[MacAnDàil]

I just read about this in Lehmann, Alise et Martin-Berthet, Françoise, Lexicologie : sémantique, morphologie, lexicographie (Armand Colin : 2013) for my thesis.
They mention that co-hyponyms can have synonym- or antonym-like relationship to each other, like 'buy' and 'steal' that are both subsets of 'procure'.

[mèþru]

Or, going even more pedantic, conifers are a subtype of Gymnosperm ("naked seeds", referring to the fact that their seeds are not enclosed within an ovary), also including ginkoes, cycads and gnetophytes (comprising the three geni Gnetum, Welwitschia and Ephedra). These are usually with the only other group of plants with seeds, or spermophytes: angiosperms, the flowering plants.
so it should be conifers vs woody angiosperms

[alynnidalar]

This is only tangentially related to this thread, but you guys might find it interesting anyway: what a neural network thinks is the opposite of a given category.

(if you're curious about how the neural network works in the first place, which gives some useful context to the above post, here's an explanation)

[Ryusenshi]

In topology, an "open set" seems like the opposite of a "closed set". There is the name, of course; plus, the complement of an open set is a closed set (and vice versa). But, in fact, most sets are neither open nor closed; it's even possible to be both.

There are lots of similar examples in maths and science:
- "increasing function" and "decreasing function" (most functions are neither)
- "odd function" and "even function" (ditto)
- In thermodynamics, "intensive property" and "extensive property"
- etc.

[Kuchigakatai]

Oh, I can think of some fun ones involving languages.

Mandarin vs. Cantonese (for what's spoken in North America's Chinatowns)

Chinese vs. Japanese (for crazy logographies still used)

Japanese vs. Korean (regarding media products people care about outside East Asia... maybe I should rename this "anime" vs. "k-pop")

Egyptian vs. Sumerian (if both old-ass languages and the Bronze Age are your thing...)

Hebrew vs. Arabic (when beginning to learn or learn about Semitic languages)

Arabic vs. Persian (it was quite the struggle at the beginning of the last millenium)

Old French vs. Old Occitan (for cultural prestige among medieval Romance languages)

Latin vs. Greek (in the Roman Empire)

Quechua vs. Aymara

Spanish vs. French (when beginning to learn or learn about Romance languages)

Spanish vs. Portuguese (when talking about South America)

French vs. German (in the European Union)

English vs. French (for domination as the world's lingua franca... hey, French was somewhat of a plausible option before the World Wars)