Piscator dicit se hodie e portu non exiturum esse, quia fluctus nimis magni sunt.

Because this is an indirect statement after dicit.

In Latin, when the subject of the main verb and the subject of the indirect statement are the same person, Latin normally uses the reflexive pronoun se.

So:

• Piscator dicit se ... exiturum esse = The fisherman says that he ... will go out
• Here he means the fisherman himself

If Latin used eum, that would normally mean some other male person, not the fisherman.

So se tells you clearly: the person who is speaking and the person who is supposedly going out are the same.

Because after verbs of saying, thinking, knowing, perceiving, and similar verbs, Latin often uses an indirect statement construction.

That construction is:

• accusative subject
  • infinitive verb

So after dicit:

• se = accusative subject of the indirect statement
• exiturum esse = infinitive expressing what he says

A literal breakdown is something like:

• Piscator dicit
• se
• hodie e portu non exiturum esse

= The fisherman says = himself = not to be about to go out from the harbor today

Natural English: The fisherman says that he will not go out from the harbor today.

Latin prefers this accusative-and-infinitive structure where English usually uses that + finite verb.

Exiturum esse is the future infinitive active of exire (to go out).

It is made from:

• the future active participle: exiturus, -a, -um = about to go out / going to go out
• plus esse

So:

• exiturum esse = to be about to go out, or in smoother English, to be going to go out / to go out in the future

Because the fisherman is talking about something that has not happened yet, Latin uses the future infinitive in the indirect statement.

Because it agrees with se, and se is accusative singular.

In an indirect statement, the subject is in the accusative. Since se is accusative singular and refers to piscator (masculine singular), the participle must also be:

• masculine
• singular
• accusative

So:

• nominative masculine singular: exiturus
• accusative masculine singular: exiturum

That is why Latin says:

• se exiturum esse

not

• se exiturus esse

In normal prose, Latin usually includes esse in the future infinitive.

The full future infinitive is:

• exiturum esse

Here:

• exiturum carries the idea of future action
• esse completes the infinitive construction

In some poetry, and occasionally in compressed style, forms of esse can be omitted, but for standard prose and for learners, you should expect:

• future participle + esse

So the sentence is behaving exactly as you would expect in ordinary Latin.

Because non negates the verbal idea of the indirect statement: going out.

So:

• se hodie e portu non exiturum esse = that he will not go out from the harbor today

Latin often puts non directly before the word or phrase it is negating. Here it naturally comes before the future infinitive phrase.

If you moved non elsewhere, the emphasis could change slightly, but this placement is straightforward and normal.

Yes, e portu and ex portu can both mean out of/from the harbor.

A few useful points:

• e/ex means out of, from
• it takes the ablative case
• portu is the ablative singular of portus

As for e versus ex:

• ex is the fuller form
• e is a shortened form often used before consonants

Since portu begins with a consonant, e portu is perfectly normal.

So the important grammatical point is really:

• e/ex + ablative
• therefore portu, not portum

Because the preposition e/ex requires the ablative case.

This is a standard Latin rule:

• e/ex + ablative = out of / from
• in + ablative can mean in/on
• ad + accusative means to/toward
• and so on

So:

• nominative: portus
• accusative: portum
• ablative: portu

Since the idea is from the harbor, Latin uses:

• e portu

Because quia fluctus nimis magni sunt is a separate subordinate clause, not part of the accusative-and-infinitive construction.

The indirect statement is only:

• se hodie e portu non exiturum esse

After that, quia introduces a normal clause with its own subject and verb:

• fluctus = subject, nominative plural
• sunt = finite verb
• magni = predicate adjective agreeing with fluctus

So the grammar is:

1. Main clause: Piscator dicit
2. Indirect statement: se ... non exiturum esse
3. Causal clause: quia fluctus nimis magni sunt

Since fluctus is the subject of sunt, it must be nominative, not accusative.

Because magni is a predicate adjective with fluctus.

In the clause:

• fluctus nimis magni sunt

the structure is:

• fluctus = nominative plural subject
• magni = nominative plural adjective describing the subject
• sunt = are

So magni must match fluctus in:

• gender: masculine
• number: plural
• case: nominative

Hence:

• fluctus ... magni sunt = the waves are too large

If you had magnos, that would be accusative plural, which would not fit here.

Here it is plural.

This is one of those forms that can confuse learners, because fluctus belongs to the fourth declension, and some of its forms look alike.

For fluctus, -us (wave), masculine, fourth declension:

• nominative singular: fluctus
• nominative plural: fluctus
• accusative singular: fluctum
• accusative plural: fluctus

So the form fluctus can be singular or plural depending on context.

Here we know it is plural because:

• the verb is sunt = are
• the adjective is magni = large, plural

So fluctus nimis magni sunt must mean the waves are too large.

Because quia introduces a normal finite subordinate clause, not an indirect statement.

After dicit, Latin uses the accusative-and-infinitive for what is being said:

• se ... non exiturum esse

But quia means because, and clauses introduced by quia normally use a regular finite verb:

• fluctus nimis magni sunt

So the sentence mixes two different constructions:

• indirect statement after dicit
• causal clause after quia

That is completely normal Latin.

Hodie means today, and it modifies the action exiturum esse.

So the sense is:

• he says that he will not go out today

Its position is flexible, because Latin word order is much freer than English word order. Here it sits inside the indirect statement, close to the verbal idea it belongs with.

Latin often places adverbs where they fit naturally for rhythm or emphasis rather than according to a fixed English-style rule.

So:

• se hodie e portu non exiturum esse

is a normal way to say:

• that he will not go out from the harbor today

Because nimis is an adverb meaning too much, excessively, too.

It modifies the adjective magni:

• magni = big / large
• nimis magni = too big / excessively large

This is a common Latin pattern:

• nimis celer = too fast
• nimis longus = too long
• nimis multi = too many

So fluctus nimis magni sunt literally means:

• the waves are excessively large

which in natural English becomes:

• the waves are too big

Yes, often quod and quia can both introduce a causal clause meaning because.

So both of these would be possible in many contexts:

• quia fluctus nimis magni sunt
• quod fluctus nimis magni sunt

There can be stylistic and contextual differences in some authors, but for a learner, the main point is:

• quia commonly means because
• it introduces the fisherman’s reason for not going out

So nothing unusual is happening here; this is a standard causal clause.

Yes: exire is a compound of ire (to go) with the prefix ex- (out), so it is somewhat irregular.

Its principal parts are:

• exeo
• exire
• exii/exivi
• exitum

Its future active participle is:

• exiturus, -a, -um

So in the accusative masculine singular, it becomes:

• exiturum

That form may look strange at first, but it is exactly what you should expect from exire.

So:

• se ... exiturum esse = that he is going to go out / will go out

except here, with non, it becomes the negative:

• that he will not go out