Learn Hardcore Latin: Hodie dies frigidus est, sed domus calida est. - Today the day is cold, but the house is warm.

Both dies frigidus est and dies est frigidus are correct and mean the same thing.
The most important information is often placed towards the end, but in a simple sentence like this there’s no big difference.
You could also see frigidus est dies or even est dies frigidus in Latin.

So in this sentence, the order subject – adjective – verb is perfectly normal, but not the only possible order.

What case are dies and domus, and why?

Both dies and domus are in the nominative singular.

The nominative is used for the subject of the sentence.
Here, dies (day) is the subject of frigidus est (is cold).
domus (house/home) is the subject of calida est (is warm).

So: The *day is cold, but the house is warm.*
Both “day” and “house” are doing the “being,” so they are nominative in Latin.

Why is it frigidus with dies, but calida with domus? Why are the endings different?

Latin adjectives must agree with the nouns they describe in:

Gender (masculine / feminine / neuter)
Number (singular / plural)
Case (nominative / accusative / etc.)

In this sentence:

dies is masculine singular nominative → adjective must be masculine singular nominative → frigidus
domus is treated as feminine singular nominative → adjective must be feminine singular nominative → calida

So:

dies frigidus = a cold day
domus calida = a warm house

The different endings on frigidus and calida show the different genders of the nouns they agree with.

Is dies masculine or feminine? I thought words ending in -us were masculine and -a were feminine.

The simple rules “-us = masculine” and “-a = feminine” work often, but not always.

dies (day) belongs mainly to the 5th declension, where the nominative singular often ends in -es, not -us.
In Classical Latin, dies is usually masculine (except sometimes in poetry or special meanings).

So in this sentence:

dies is treated as masculine, so the adjective is frigidus (masc.), not frigida (fem.).

The endings -us and -a in adjectives (like frigidus, frigida, frigidum) change to match the noun’s gender, not the other way around.

What gender and declension is domus? It doesn’t look like a regular 1st or 2nd declension noun.

Domus is a bit irregular:

It is usually feminine in Latin.
It mostly belongs to the 4th declension (nominative singular -us, genitive singular -us), but it can sometimes show forms that look like 2nd declension.

For a beginner, it’s enough to remember:

domus = house, home
It’s feminine, so you use feminine adjectives: domus calida, domus magna, domus nova, etc.

Where are the English words “a” and “the” in the Latin? How do you know if it’s “a cold day” or “the cold day”?

Latin has no separate words for “a” or “the” (no articles).

dies frigidus can mean “a cold day” or “the cold day”.
domus calida can mean “a warm house” or “the warm house”.

Whether you translate with “a” or “the” depends on the context and what sounds natural in English.
Here, “Today is a cold day, but the house is warm” is a normal English way to express it, but the Latin itself does not force “a” or “the” either way.

What exactly is hodie? Is it related to dies?

Hodie is an adverb meaning “today”.

Historically, hodie comes from hoc die = on this day:

hoc = this (neuter singular, “this thing”)
die = ablative of dies (day) → “on the day”

Over time, hoc die fused into one word, hodie, which behaves like an adverb.
You don’t change its form: it is just hodie, regardless of case, number, or gender.

Why is est (is) repeated? Could you say Hodie dies frigidus, sed domus calida without the second est?

Latin can omit forms of esse (est, “is”) when the meaning is still clear, especially in simple or poetic style. So:

Hodie dies frigidus, sed domus calida is understandable and possible.

However:

In basic prose and for learners, it’s very common and clearer to keep est with each clause:
Hodie dies frigidus est, sed domus calida est.
Each est belongs to its own little sentence:
1. Hodie dies frigidus est.
2. Domus calida est.

So the repetition is not required, but it’s perfectly normal and very clear Latin.

Why use sed here, and could other words like autem or at be used instead?

Sed is the basic word for “but” and is the most natural choice here:

sed = “but” in a simple, straightforward contrast: cold day, but warm house.

Other options:

autem = “however / on the other hand”; it usually does not come first in its clause and has a slightly weaker, more “commenting” tone:
- Hodie dies frigidus est; domus autem calida est.
at = “but / yet / on the contrary”; often stronger, used when you’re pushing back against something more forcefully.

In a beginner’s sentence showing a simple contrast, sed is the best and most neutral choice.

Could you say Hodie frigidum est instead of Hodie dies frigidus est?

Yes, Hodie frigidum est is a natural and common way to say “It is cold today” in Latin.

Here, frigidum est is an impersonal expression: literally “it is cold,” with no explicit noun like dies.
Hodie dies frigidus est is more literally “Today the day is cold,” which is also correct, but a bit more explicit.

Both are good Latin; the version with dies just names the noun “day,” while the impersonal frigidum est works more like English “it’s cold.”