Lucia domi amicae rescribere conata est, sed unum mendum statim emendavit.

Domi means at home. It is a special old locative form of domus.

Latin often uses:

• domi = at home
• in domo = in the house

So domi is the more idiomatic way to say that Lucia was at home, not just physically inside a house.

Here amicae is dative singular, meaning to a friend or to her friend.

We know this because rescribere can take the person replied to in the dative:

• alicui rescribere = to write back to someone

So amicae rescribere means to write back to a friend.

It is true that amicae could also be:

• genitive singular = of a friend
• nominative plural = female friends

But in this sentence, the verb relationship makes dative singular the correct reading.

Because it depends on conata est.

The verb conor often takes a complementary infinitive to show what someone tries to do:

• conata est rescribere = she tried to write back

So rescribere is not the main verb of the sentence. It completes the meaning of conata est.

Conata est is from conor, conari, conatus sum, which is a deponent verb.

A deponent verb:

• has passive-looking forms
• but an active meaning

So although conata est looks a bit like a passive form, it actually means:

• she tried
• she attempted

In this sentence, it is perfect tense: she tried.

Because conata must agree with Lucia.

Since Lucia is:

• feminine
• singular
• nominative

the participle must also be:

• feminine
• singular
• nominative

So:

• conatus would be masculine
• conata is feminine
• conatum would not fit here

They are formed differently.

Conata est is the perfect of a deponent verb, and deponent perfect forms use:

• a perfect participle
• plus a form of sum

So:

• conata est = she tried

But emendavit is a regular active perfect, formed as a single word:

• emendavit = she corrected

So the difference is grammatical, not a difference in meaning.

Because mendum is a neuter noun, and unum has to agree with it.

Here:

• mendum = mistake, fault, error
• unum = one or a single

Both are accusative singular neuter, because unum mendum is the direct object of emendavit.

So:

• unum mendum = one mistake or a single mistake

Because it is the direct object of emendavit.

Ask: What did Lucia correct? Answer: unum mendum

That is why mendum is accusative, and unum matches it.

Latin often leaves out possessive words like her, his, or their when the meaning is obvious from context.

So amicae by itself can mean:

• to a friend
• to the friend
• to her friend

depending on the situation.

If Latin wanted to be more explicit, it could say amicae suae.

Because Latin does not have articles.

So nouns like amicae and mendum do not themselves tell you whether English should use:

• a
• an
• the

You choose that from context when translating.

For example:

• amicae could be to a friend or to the friend
• mendum could be a mistake or the mistake

Latin word order is much more flexible than English word order because the endings show each word’s role.

Here:

• Lucia is the subject
• domi sets the place
• amicae is dative
• rescribere goes with conata est
• unum mendum is the object of emendavit
• statim modifies emendavit
• sed introduces a contrast

So the sentence does not need rigid English-style order to be understood.

This order gives a natural flow:

• first the person: Lucia
• then the setting: domi
• then what she tried to do
• then the contrast: sed
• then what she actually corrected right away

Literally, rescribere means to write back or to write in reply.

The prefix re- here gives the sense of:

• back
• in return
• in reply

So it is a very natural verb for replying to a letter or message.