Saluton Kamaradoj!

Because of my methods of learning esperanto, I kinda do bypass some grammar points and learn other things. As a result, I still have some concerns about the uses of adverbs vs adjectives. To clarify:

If you don't have a noun in the object of a copula sentence, you use an adverb in the object?
e.g. Mi estas bone, La kato estas stulte.

If you are using a participle like -ita, you use 'a' as the last vowel, right?
e.g. Mi estas kolerigita (not that you'd say that, but still), La pordo estas fermita.

If there is a noun as part of the object of a copula sentence, you use an adjective?
e.g. Mi estas bona homo.

Is this right? Please correct me if necessary. At the moment it's debatable if my understanding of other's writing is better than my own writing, and I'd like this to change.

Dank' por cxiuj via helpo!

Everything you've written seems to be correct, with the exception of your first question: in both those cases, one would use an adjective (viaekzemple, "La kato estas stulta."). However, when the noun (as the subject) is omitted from the sentence, any adjectives refering to it must be changed to adverbs.

For instance:

"Estas teorio akceptita, ke la kontinentoj disdrivas."

compared with

"Estas akceptite, ke la kontinentoj disdrivas."

"La tempuraturo estas tre varma cxi-cxambre."

compared with

"Estas tre varme cxi-cxambre."

It is an extremely useful peice of knowledge, since it helps to prevent awkward constructions, ekz.

"Via nepovo veni estas domagxa" (an unlikely construction)

It is more natural to begin the sentence with the adverb-

"Domagxe ke vi ne venos."

Benjameno

Cheers, that had been confusing me for a while.

You would have to say "Mi estas bona" and "La kato estas stulta".

"Bona" describes "me"; pronouns are grammatically treated as nouns, so you have to have an adjective to describe a noun. Similarly, the cat is being described in the second sentence. A cat is also a noun, so you have to describe it with an adjective. All Esperanto adjectives end in -a, so you'd need in -a ending either way.

If you wanted to describe the verb "estas", you would use an adverb, which is the -e ending. But describing "estas" doesn't actually make much sense. To describe the verb, you'd have to change the verb to have the sentence make much sense. Some choices might be "Mi fartas bone" (I fare well/ I am doing well/ I am well), or "La kato kondutas stulte" (the cat behaves stupidly)

Wouldn't kato be katon? Because there has to be an object, so the object is the kato.

Ok I see, dank' Erinja! So basically adverbs are still only used to describe verbs, but if you feel so you can use 'estas' to mean 'it is' and then use and adverb as an adjective, or you can change the verb completely. Now it's all coming together ha ha

Kato can't be katon. The -n is not used with "estas", because there is no object. Why? An object, by definition, is the thing being acted on by the verb. So in "Mi manĝas pomon", the apple is the object, because it is being eaten. The eating is being done on the apple. But in "I am a student", what is "being been"? The mere fact that "being been" makes no sense (as opposed to "being eaten", "being read", etc) is a clue that something is wrong here. In fact, "to be" isn't an action that one thing can perform on another, either in English or in Esperanto. Therefore the -n is never used with forms of "to be" (esti, estas, estos, estis, etc)

Regarding "dank'", you really have to say" dankon". You can't abbreviate anything with an -n ending with the apostrophe. Similarly, you can't say "salut'", because that would have to mean "saluto" by definition, and not "saluton"

The issue with "estas" is that you can only use "estas" to mean "it is" in cases where there is no noun present. So if you were to say "Kato estas stulta", then "estas" definitely can't mean "it is", because now your sentence would say "A cat it is stupid", which is ungrammatical.

We use adverbs in cases where "estas" means "it is" because these are sentences with no subject. If I say "Estas varme", there is no noun. And if there is no noun present, how can I possibly use an adjective to describe it? Instead, since I have only a verb (estas), I have to use an adverb to describe it. Because adjectives describe nouns and adverbs describe verbs.

So we never use adverbs as adjectives, or vice versa. Rather, we have to describe the right part of speech with the right part of speech. And what is "right"? You have to look at what's in the sentence. Adjectives don't hover in nothingness in Esperanto. You can't say "Estas varma", and say that "varma" describes in invisible pronoun "ĝi". Rather, you have to say "Estas varme" (you are describing the verb using an adverb). Or, if you are talking about an actual *thing* that is hot, you would say "Ĝi estas varma", ĝi being the thing that happens to be hot. Ĝi is a pronoun so it is treated as a noun grammatically, and therefore described using an adjective.

Take note that when we translate "estas" as "it is", there is no real "it", as someone has mentioned before. This is not truly "it". "It" doesn't even exist. Rather, "estas" in these cases is a verb without a subject. In English we can't have a verb without a subject, but in Esperanto we can. The only reason that "estas" is ever rendered as "it is", is because the English language cannot accept a verb without a subject, so we have to include a sort of fake dummy subject "it", as a placeholder.

I just don't know what to call the second noun in the copula, I called it the object (which does use 'n'), but is it mean to be the second clause or something like that? But yeah 'esti' isn't an action, it instead describes the relationship of existence between one thing/quality/action and another thing/quality/action. Blimey, I just can't think of the name for those 'things'... clauses? entities? I know in lojban they can be called 'arguments' and verbs are called 'functions', but that's only useful for computer programmers ha.

The use of 'estas' is very slavic in nature in my eyes, it reminds me of Russian except the copula is never used in the present, so it's just 'klassno' (classy), you wouldn't say 'it is classy' or 'is classy', just 'classy' in the form that an adverb should be in.

iel, dankon cxiuj por cxiuj via helpo (this sounds REALLY odd, but I just can't place it... )

ceigered:I just don't know what to call the second noun in the copula

Predicative when it is a noun, attribute of the subject when it is an adjective, IIRC.

But yeah 'esti' isn't an action

To my students I usually describe transitive verbs as arrows pointing to their object, and the verb 'esti' as an equal sign.

mnlg:

ceigered:I just don't know what to call the second noun in the copula

Predicative when it is a noun, attribute of the subject when it is an adjective, IIRC.

But yeah 'esti' isn't an action

To my students I usually describe transitive verbs as arrows pointing to their object, and the verb 'esti' as an equal sign.

Hey that's a great analogy... Math really is a language!
What's IIRC mean? Everytime I see it I think of computer coding for some reason... :S