Mense Martio primi flores in horto apparent, et avia gaudet.

Because this phrase expresses time when: in the month of March / in March.

Latin often uses the ablative for time when something happens. So:

• mensis = month
• mense = in the month
• Martius = March
• Martio = March in the ablative, agreeing with mense

So mense Martio literally means in the month of March.

Latin can sometimes express in March in more than one way, but here the sentence uses the fuller expression mense Martio, literally in the month of March.

This is a very normal Latin way to say it, and it is slightly more explicit than just naming the month alone. For a learner, it is helpful because it clearly shows the ablative of time when.

So:

• mense Martio = in March
• literally: in the month of March

Because primi has to agree with flores.

flores is:

• masculine
• plural
• nominative (the subject)

So the adjective must also be:

• masculine
• plural
• nominative

That gives primi.

So:

• primi flores = the first flowers

The other forms would mean different things:

• prima = feminine singular or neuter plural, so it does not match flores
• primos = masculine plural accusative, which would not fit if flores is the subject

There are two main clues:

1. flores is in the nominative plural form.
   The nominative is the case usually used for the subject.

2. apparent is plural.
   It means they appear. That matches flores = flowers.

So the grammar lines up like this:

• primi flores = subject, the first flowers
• apparent = verb, appear

Because in can take either the ablative or the accusative, depending on the meaning.

• in + ablative = in / on a place, showing location
• in + accusative = into / onto a place, showing motion toward

Here the flowers are appearing in the garden, meaning they are located there, not moving into it. So Latin uses:

• in horto = in the garden

If it were motion toward the garden, Latin would use the accusative:

• in hortum = into the garden

apparent is the 3rd person plural present active indicative of appareo, apparere, meaning to appear.

So:

• apparet = he/she/it appears
• apparent = they appear

Since flores is plural, the verb must also be plural:

• primi flores apparent = the first flowers appear

Because its subject is avia, which is singular.

• avia = grandmother
• gaudet = she rejoices / is glad

So:

• primi flores apparent = plural subject + plural verb
• avia gaudet = singular subject + singular verb

Latin verbs change form to match the number of their subject, just as English does in a more limited way.

gaudet comes from gaudeo, gaudere, which means to rejoice, to be glad, or to take delight.

So avia gaudet can be understood as:

• grandmother rejoices
• grandmother is glad
• grandmother is happy

All of these are reasonable English translations depending on style. The Latin verb has a feeling of joy or delight, not just a neutral statement of emotion.

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

So a Latin noun like horto can mean:

• in a garden
• in the garden

and avia can mean:

• a grandmother
• the grandmother

The exact sense usually comes from the context. In this sentence, English translators often choose the because it sounds natural:

• the first flowers
• in the garden
• the grandmother rejoices

But Latin itself does not state the article.

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

English relies heavily on order:

• The flowers appear in the garden

Latin can move parts around more freely because endings show what each word is doing:

• flores is clearly the subject
• horto is clearly ablative after in
• Martio agrees with mense

So Mense Martio is placed first to set the scene: In March. That is a very natural Latin way to begin the sentence.

Here it means the first flowers, that is, the earliest flowers to appear.

Latin primus can mean first in several senses:

• first in order
• first in rank
• first in time

In this sentence, because it is talking about March and flowers appearing, the meaning is clearly first in time: the earliest flowers of the season.

Yes. avia most commonly means grandmother, but in some contexts it can also refer to an old woman. In a basic learning sentence like this, grandmother is the expected meaning.

Grammatically, here avia is:

• nominative singular
• the subject of gaudet

So whatever meaning you choose from context, it is one female person who is rejoicing.

Yes.

The two clauses are:

1. Mense Martio primi flores in horto apparent
2. et avia gaudet

They are joined by et = and.

So the structure is:

• first statement: the flowers appear
• second statement: grandmother rejoices

This is a simple example of two coordinated main clauses connected by et.