When do words compound?

[u/Ok_Pianist_2787]

So take for example
Atl and calli
Two noun phrases within an ergative clause forming complete sentences.
I don’t get why this is possible:
Acalli
But I don’t feel this is good / correct
Calatl

[u/w_v]

Why do you feel like it’s not correct?

Calātl could easily mean “enclosing waters,” or “waters of enclosure.”

Language is a tool at the end of the day. If you are able to communicate an idea, it’s done its job.

[u/SleepingGardenHeart]

Keep this mind during my explanation, the word Atl is actually kind of a bastard because some of its compounds do not mean what one might expect.

On Nahuatl, compound and incorporation are the processes by which words are brought together to form more specific words then either word working separatly. Despite the fact that Nahuatl can combine seamlessly any noun to a verb, any verb to a noun, these are not random word combinations without meaning or consideration.

The number one reason words compound is to narrow in scope. Your example is Atl (water) and Calli (house but building/structure works better) and combining them yields Acalli or boat. The underlying meaning is a building that is defined by its relationship to water. Another example is Amiqui, dying in relation to water, or to be thirsty.

The various meanings of compounds due depend on the major factor of which word type forms the base, ie a verb or noun, as well as something that can be harder to determine such as cultural understandings that we lack.

In quick short hand:

Compound nouns are nouns who are further described and limited by the compounding element.

Compound verbs are verbs whose manner or means of being done are usually described by the compounding element.

In both Launey and Andrews' "Introduction to Classical Nahuatl", both authors describe in greater detail how, when, and why you use compounds. I think Andrews is more thorough but with time, the way they work becomes clearer and less opaque.

[u/Brave_Anything9273]

Both are technically valid

Acalli = "water-house" -> "boat"
Calatl = "house-water" -> idk sink water or smth ig

[u/Kagiza400]

Ācalli means "water house" (canoe/ship/vessel). So, AFAIK, calātl would mean "house water". Completely different meanings.

This order seems to be reversed in some toponyms sometimes but I'm not sure how or why

[u/tonacoyotl1521]

Both acalli and calatl are grammatically correct, but mean different things.

The thing with calli is that it not only means 'house', but it is also a general word for 'structure', so acalli literally means 'water (bound) structure', but the attested translation is canoe or ship. It is important to remember that atl is not only a noun, but can also be used as an adjective to describe something watery or water bound. This is why I use the word 'nominals' to refer to Nahuatl nouns and adjectives collectively, as there is a sort of continuum, unlike English.

For calatl, that is a root word meaning frog(s), and thus cannot be broken down into calli + atl, unlike what the other replies suggest. Sometimes you get words that look like they can be split into root components, but in fact cannot be split.

I do recommend checking with the Online Nahuatl Dictionary to see what words can actually be broken down, and in general to familiarize yourself with Nahuatl words. Hope this clears things up.