Learn Hardcore Latin: Mater respondet patri et dicit: "Puer foris currit." - Mother answers father and says: "The boy is running outside."

māter – nominative singular, subject of respondet and dicit.
patrī – dative singular, indirect object of respondet: she answers to the father.
puer – nominative singular, subject of currit in the quoted sentence.

So in simple terms:

Mater does the actions “responds” and “says.”
Patri is the one to whom she responds.
Puer is the one who is running.

Why is it puer and not puerum?

Puer is the subject of the verb currit, so it must be in the nominative case.

nominative: puer = the boy (as subject)
accusative: puerum = the boy (as object)

In Puer foris currit, the boy is the one doing the running, so nominative puer is required, not accusative puerum.

What does foris mean exactly, and how is it different from foras?

Foris here is an adverb meaning “outside” / “out of doors”.

There is a subtle traditional distinction:

foris – “outside” with a sense of location
- puer foris est – the boy is outside
- puer foris currit – the boy runs outside (i.e. in an outdoor location)
forās – “outside” with a sense of motion to the outside
- puer forās currit – the boy runs (from inside) to the outside

In practice, especially in easier or later Latin, the distinction is often not emphasized, and learners will often see foris simply glossed as “outside.”

Could the word order in Puer foris currit be different?

Yes. Latin word order is relatively flexible. You might see:

Puer currit foris
Foris puer currit
Currit puer foris

All would still mean something like “The boy runs outside.”
However:

Putting puer first makes the boy the focus.
Putting foris first can emphasize where he is.
Often, simple sentences end with the verb: Puer foris currit or Puer foris currit is very natural.

Your sentence is already perfectly good and idiomatic.

Why is the present tense currit used for “is running”? Doesn’t Latin need a special progressive form?

Latin has no separate “-ing” progressive tense like English (“is running”).

The present indicative normally covers both:

currit = he runs
currit = he is running

Context decides which English translation is better.
So Puer foris currit can be “The boy runs outside” or “The boy is running outside.” Both are correct translations of the same Latin tense.

Why do we have both respondet and dicit? Isn’t respondet already “she replies / she answers”?

Both verbs are meaningful:

respondet patri – she answers the father (this tells you that she is replying to something he said).
et dicit – and she says (this introduces the actual words she speaks).

You could write just:

Māter patri respondet: “Puer foris currit.”

and it would still be fine. But respondet … et dicit makes the structure very explicit for learners: first we are told that she answers, then we are told exactly what she says.

Is the word mater always feminine, and pater always masculine?

Yes:

māter, mātris – grammatically feminine, means mother.
pater, patris – grammatically masculine, means father.

These are natural-gender nouns whose grammatical gender matches their meaning. Their gender does not change with case; only the endings change:

nominative: māter, pater
dative: mātrī, patrī
accusative: mātrem, patrem, etc.

What are the dictionary forms (principal parts) of respondet, dicit, and currit, and what person/number are they?

Each is 3rd person singular present active indicative:

respondet
- dictionary: respondeō, respondēre, respondī, respōnsum
- meaning: he/she/it responds / answers
dicit
- dictionary: dīcō, dīcere, dīxī, dictum
- meaning: he/she/it says
currit
- dictionary: currō, currere, cucurrī, cursum
- meaning: he/she/it runs

All three are present tense, 3rd person, singular, active, indicative.

Why is there a colon (:) and quotation marks for the spoken words? Did Romans write like that?

The colon and quotation marks are modern editorial conventions to show direct speech clearly:

Māter respondet patri et dicit: “Puer foris currit.”

Classical Roman manuscripts did not use modern punctuation or quotation marks the way we do. Editors of Latin texts today add them to make reading easier.

So the punctuation is modern, but the grammar—using dicit plus the exact words spoken—is genuinely Latin and is how direct speech was expressed.