Iunius longos dies habet, et puellae mense Iunio ad litus ire volunt.

They are two different cases of the same word.

• Iunius is nominative singular, used for the subject: June has long days.
• Iunio is ablative singular, used in the time expression mense Iunio: in June / in the month of June.

So the ending changes because the word is doing a different job in each part of the sentence.

It is originally an adjective meaning June, as in mensis Iunius = the month of June. But Latin often uses month names by themselves, so Iunius can function like a noun meaning simply June.

That is why you see:

• Iunius = June
• mense Iunio = literally in the June month

Because longos dies is the direct object of habet.

• habet = has
• What does June have? longos dies = long days

A direct object normally goes in the accusative case, so:

• dies is accusative plural here
• longos is also accusative plural masculine, agreeing with dies

The adjective and noun must match in case, number, and gender.

That is a very common question. Dies is one of those nouns whose singular and plural can look the same in some forms.

Here you know it is plural mainly because of longos:

• longos = masculine accusative plural
• so dies must also be plural

So longos dies can only mean long days, not long day.

The noun dies, diei is usually masculine, especially in ordinary meanings like day or days. That is why the adjective is masculine too:

• longos dies

You may sometimes learn that dies can be feminine in certain special uses, but here it is simply masculine.

Because here puellae is nominative plural, the subject of volunt.

• puellae = girls
• volunt = they want

A beginner may notice that puellae could also be:

• genitive singular = of the girl
• dative singular = to/for the girl
• nominative plural = girls

But in this sentence, volunt is plural, so puellae must be the plural subject: the girls want.

Both words are in the ablative singular.

• mense = in the month
• Iunio = June

Together they mean in June or more literally in the month of June.

This is a standard Latin way to express time when something happens. The ablative is often used for that idea.

Latin can sometimes express the month simply with the ablative, but mense Iunio is a very natural and explicit phrase meaning in the month of June.

So mense is there to make the time expression fuller and clearer. It is not unusual or redundant; it is just a standard Latin way of saying it.

Because ad with the accusative usually expresses motion toward something.

• ad = to, toward
• litus = shore, beach, seashore

So ad litus ire means to go to the beach/shore.

That is different from a phrase meaning at the beach, which would use a different construction.

Litus is a neuter noun, and for many neuter nouns the nominative and accusative singular have the same form.

So:

• nominative singular: litus
• accusative singular: litus

Even though the form does not change, it is still accusative here because ad requires the accusative.

Because Latin uses an infinitive after verbs like want, can, must, begin, and so on.

• volunt = they want
• ire = to go

So ire volunt literally means they want to go.

This is called a complementary infinitive.

Latin word order is much more flexible than English word order because the case endings show how the words function.

Putting the verb at or near the end is very common in Latin. So:

• puellae mense Iunio ad litus ire volunt

is perfectly normal Latin word order.

English depends heavily on word order, but Latin depends more on endings.

Latin does not have articles like English the and a/an.

So:

• puellae can mean girls or the girls, depending on context
• litus can mean the beach, a beach, or simply beach/shore, depending on context

When translating into English, you add the or a if it sounds natural.

Yes. Et is the ordinary Latin word for and.

It connects the two parts of the sentence:

• Iunius longos dies habet
• et puellae mense Iunio ad litus ire volunt

So it simply links the two statements together.