Magister dicit titulum bonum esse, sed in secunda linea mendum parvum latere.

Because after dicit (says), Latin often uses an indirect statement construction.

In English, we say:

• The teacher says that the title is good.

In Latin, instead of using a word exactly like that, Latin usually puts:

• the subject of the reported statement in the accusative
• the verb of the reported statement in the infinitive

So:

• titulus est bonus = the title is good
• but after dicit it becomes titulum bonum esse = that the title is good

That is why titulum is accusative.

For the same reason: this is an indirect statement.

A direct statement would be:

• Titulus bonus est. = The title is good.

But after dicit, Latin changes it into indirect statement form:

• titulum bonum esse

Here:

• bonum agrees with titulum
• esse is the infinitive to be

So Latin is literally saying something like:

• The teacher says the title to be good

That sounds unnatural in English, but it is standard Latin grammar.

Because bonum describes titulum, so it must agree with it.

Since titulum is:

• masculine
• singular
• accusative

bonum must also be:

• masculine
• singular
• accusative

This agreement is exactly like what would happen in a normal sentence:

• titulus bonus = nominative
• titulum bonum = accusative

Because the second half is also an indirect statement depending on dicit.

The teacher says two things:

1. titulum bonum esse = that the title is good
2. mendum parvum latere = that a small mistake is hidden / lurking

So dicit governs both infinitive phrases.

Latin often avoids repeating the main verb structure. Once dicit is established, both reported ideas can stay in indirect statement form.

Because the verb there is not to be. It is latere.

• esse = to be
• latere = to lie hidden, to be concealed, to escape notice

So:

• titulum bonum esse = that the title is good
• mendum parvum latere = that a small mistake is hidden

Both are indirect statements, but they use different infinitives because they express different ideas.

Latere means to lie hidden, to be concealed, or to escape notice.

In this sentence, it suggests that the mistake is present but not obvious. Depending on context, you might understand it as:

• a small mistake is hidden
• a small mistake is lurking
• a small mistake is concealed
• there is a small hidden mistake

It is a nice Latin verb because it conveys the idea that something is there, but not immediately seen.

This is a very common learner question.

In an indirect statement, the subject should indeed be accusative. Here, however, mendum is a neuter noun.

For many neuter nouns, the nominative and accusative forms are identical. So:

• nominative singular: mendum
• accusative singular: mendum

Likewise:

• nominative singular neuter adjective: parvum
• accusative singular neuter adjective: parvum

So mendum parvum really can be accusative, even though it looks the same as the nominative.

Because in with the ablative often means in or on a place.

Here:

• in = in
• secunda linea = the second line

Since the meaning is location, Latin uses the ablative:

• in secunda linea = in the second line

If in were followed by the accusative, it would usually suggest motion into something. But here there is no motion; the mistake is located there.

Because it follows in in a sense of location.

The noun is linea, lineae (feminine, first declension), so the ablative singular is linea.

The adjective secunda must agree with linea, so it is also ablative singular feminine.

That gives:

• in secunda linea = in the second line

It is flexible, but not unusual for Latin.

The sentence is:

• Magister dicit titulum bonum esse, sed in secunda linea mendum parvum latere.

A more rigid English-style order might be something like:

• Magister dicit titulum bonum esse, sed mendum parvum in secunda linea latere.

But Latin often places phrases where they are rhetorically useful. Here in secunda linea comes early in the second clause to emphasize where the mistake is hidden.

Latin word order is guided less by fixed syntax and more by emphasis, balance, and style.

Yes. Sed most commonly means but.

Here it contrasts the two ideas:

• the title is good
• but there is still a small mistake in the second line

So but is the most natural translation.

Here are the main dictionary forms:

• magister, magistri = teacher
• dico, dicere, dixi, dictum = say
• titulus, tituli = title
• bonus, bona, bonum = good
• sum, esse, fui = be
• secundus, secunda, secundum = second
• linea, lineae = line, row
• mendum, mendi = fault, mistake
• parvus, parva, parvum = small
• lateo, latere, latui = lie hidden

Because the teacher is saying these things as true at the same time as the act of speaking.

Latin infinitives in indirect statement show time relative to the main verb, not absolute time in the same way English does.

So:

• esse
• latere

are present infinitives, meaning the reported actions/states are happening at the same time as dicit.

In other words:

• the teacher says the title is good
• the teacher says a small mistake is hidden

If the reported action had happened earlier, Latin would normally use a perfect infinitive instead.

Sometimes Latin can use quod clauses, especially in later Latin or in certain styles, but the normal classical construction after verbs like dicit is the accusative and infinitive.

So for a learner, the important point is:

• after dicit, expect accusative + infinitive

That is exactly what you have in:

• titulum bonum esse
• mendum parvum latere

A very helpful way is:

• Magister dicit
• titulum bonum esse
• sed
• in secunda linea
• mendum parvum latere

So you can process it as:

1. The teacher says
2. that the title is good
3. but
4. in the second line
5. that a small mistake is hidden

That makes the grammar much easier to follow.