Mater dicit se ad forum ituram esse.

Because se is the reflexive pronoun, and it refers back to the subject of the main verb, here Mater.

So Mater dicit se ... means Mother says that she herself ...

If the sentence meant Mother says that another woman is going..., Latin would normally use eam, not se.

• Mater dicit se ad forum ituram esse = Mother says that she herself is going to the forum.
• Mater dicit eam ad forum ituram esse = Mother says that that other woman / her is going to the forum.

This is a very common point in Latin indirect statement.

Because after verbs of saying, thinking, knowing, hearing, and similar verbs, Latin usually uses an indirect statement construction called the accusative and infinitive.

That means:

• the subject of the reported statement goes into the accusative
• the verb of the reported statement goes into an infinitive

So in Mater dicit se ad forum ituram esse:

• dicit = she says
• se = the subject of the reported statement, in the accusative
• ituram esse = the infinitive part

In English we would often use that:

• Mother says that she is going to the forum

Latin usually does not use a that-clause here. It uses accusative + infinitive instead.

Ituram esse is the future active infinitive of eo, ire (to go).

It is made from:

• the future participle: ituram
• plus esse

So:

• ituram esse = to be going to go, or more naturally, to be going to come/go depending on context
• here: to be going

In indirect statement, this is how Latin expresses an action that is future relative to the main verb.

So Mater dicit se ad forum ituram esse means:

• Mother says that she will go / is going to go to the forum.

Because the future participle must agree with the subject of the infinitive, which is se.

Even though se itself does not show gender, the participle does.

Here Mater is singular and feminine, so se refers to a single female person. Therefore the participle is:

• ituram = feminine accusative singular

Other possibilities would be:

• iturum esse = if the subject were masculine singular
• ituros esse = if the subject were masculine plural
• ituras esse = if the subject were feminine plural

So ituram tells you that the person going is one female.

Because the future infinitive in Latin is normally formed with:

• future participle + esse

So the full form is needed:

• ituram esse

Without esse, the grammar would be incomplete in normal prose.

You can think of it as parallel to English to be about to go or to be going to go, where the infinitive needs the verb to be.

Because ire is the present infinitive, not the future infinitive.

Compare:

• se ire = that she is going / to go
• se ituram esse = that she is going to go / will go

Latin is being more precise here. The speaker is reporting something that is still in the future from the point of view of dicit.

So if the meaning is future, ituram esse is the right form.

The future is relative to the main verb dicit.

So Mater dicit se ad forum ituram esse means:

• at the time she is speaking, the going to the forum is still in the future

In other words:

• dicit = says now
• ituram esse = will go later

This is an important idea in Latin indirect statement: the infinitive tense is often relative to the main verb, not simply an absolute tense like in English.

Because ad takes the accusative when it means to or toward a place.

So:

• ad forum = to the forum

This is standard Latin usage for motion toward something.

Compare:

• ad urbem = to the city
• ad villam = to the house/country house
• ad forum = to the forum

Some place names and a few special nouns can express motion toward without a preposition, but forum is not normally one of those in this kind of sentence.

So for ordinary movement to the forum, Latin usually says:

• ad forum

The bare accusative without a preposition is mainly used with names of towns and small islands, and with a few special words like domum.

For example:

• Romam it = he goes to Rome
• domum it = he goes home
• but ad forum it = he goes to the forum

It is not strictly required, but it is very natural Latin word order.

Latin word order is more flexible than English word order, because the endings do much of the grammatical work. So you could also find similar ideas arranged differently.

But putting the infinitive, especially esse, toward the end is very common.

So:

• Mater dicit se ad forum ituram esse

is a normal and idiomatic order.

Yes. In fact, that is usually the most natural way to explain the structure.

Latin:

• Mater dicit se ad forum ituram esse

English:

• Mother says that she is going to the forum
• Mother says that she will go to the forum

The important point is that Latin does not actually use a separate word meaning that here. Instead, it uses the accusative-and-infinitive construction.

Because this is simply the normal Latin way of reporting a statement after verbs like:

• dico = say
• puto = think
• scio = know
• audio = hear

English prefers:

• She says that she will go

Latin prefers:

• She says herself to be going to go
• in natural grammar terms: accusative + infinitive

It can sound strange when translated word-for-word into English, but it is one of the most basic and common features of Latin syntax.

Yes. Latin present tense often covers both simple present and progressive present.

So dicit can mean:

• says
• is saying

Which English translation is best depends on context.

Likewise the whole sentence could be understood as:

• Mother says that she will go to the forum
• Mother is saying that she is going to the forum

Because eo, ire is the standard irregular Latin verb meaning to go.

Its future participle is unusual-looking:

• iturus, itura, iturum

So in this sentence, because the subject is feminine singular accusative, we get:

• ituram esse

This is worth memorizing, because eo is a very common verb and some of its forms are not easy to guess.

The key things are:

1. dicit introduces an indirect statement
2. the subject of that indirect statement is se in the accusative
3. se is reflexive and refers back to Mater
4. ituram esse is the future infinitive
5. ituram agrees with se and shows feminine singular
6. ad forum means to the forum

So this sentence is an excellent example of how Latin says:

• Mother says that she will go to the forum