Retro villam hortus parvus est, ubi flores crescunt.

Because retro is being used as a preposition here, and it takes the accusative. So:

• retro = behind
• villam = the house in the accusative singular

Even though English uses behind the house to describe a location, Latin does not automatically use the ablative just because something is stationary. The preposition decides the case, and retro takes the accusative in this sentence.

Here retro means behind or at the back of.

So retro villam means:

• behind the house
• or at the back of the house

It is worth knowing that retro can also be an adverb in other contexts, meaning something like back or backward, but here it is clearly functioning as a preposition with villam.

Latin word order is much more flexible than English word order. Starting with Retro villam puts the location first:

• Retro villam = Behind the house
• hortus parvus est = there is a small garden

This is very natural in Latin. The sentence is setting the scene first, then telling you what is there.

English often prefers There is a small garden behind the house, but Latin can comfortably begin with the place.

Both are possible in Latin. Because Latin uses case endings, word order is not as fixed as in English.

In hortus parvus est:

• hortus = garden
• parvus = small
• est = is

The adjective parvus agrees with hortus in:

• gender: masculine
• number: singular
• case: nominative

So the meaning is still a small garden is / there is a small garden.

A learner should focus more on the endings than on expecting one rigid word order.

Latin often uses est simply to mean there is when introducing something that exists somewhere.

So:

• hortus parvus est literally looks like a small garden is
• but in natural English it means there is a small garden

Latin does not need a separate word for the English there in this kind of sentence.

Latin has no articles. That means it has no direct equivalent of English a, an, or the.

So:

• hortus can mean a garden or the garden
• flores can mean flowers or the flowers

You decide which is best from the context and from the given meaning.

Ubi here means where.

It introduces a clause that describes the place just mentioned:

• ubi flores crescunt = where flowers grow

So ubi connects the garden with what happens there.

It is sometimes called a relative adverb of place, because it means where rather than who, which, or that.

This is a subordinate clause:

• ubi = where
• flores = flowers
• crescunt = grow

So the whole clause means where flowers grow.

Inside that clause:

• flores is the subject
• crescunt is the verb

The clause describes hortus, the garden.

Because flores is the subject of crescunt.

• flos = flower (singular)
• flores = flowers (nominative plural)

Since flowers are the ones doing the growing, the noun must be in the nominative.

Because its subject, flores, is plural.

• flores = flowers
• crescunt = grow

In Latin, verbs must agree with their subjects in number and person. Since flores is plural, the verb must also be plural.

Crescunt is present tense, third person plural.

It means:

• they grow
• or in smoother English, simply grow

In this sentence it describes what happens in the garden generally: flowers grow there.

Yes, in sense, though where is more natural.

So:

• ubi flores crescunt = where flowers grow
• more literally in some contexts: in which flowers grow

Because the antecedent is a place (hortus), English normally prefers where.

No, Latin has more than one way to express this idea.

For example, learners may also meet:

• post villam = behind the house
• sometimes other expressions depending on style and period

But in this sentence, retro villam is perfectly straightforward and idiomatic for a learner to understand as behind the house.

The comma helps show that ubi flores crescunt is a clause giving extra information about the garden.

In modern printed Latin, punctuation is added for clarity, much like in English. Ancient Latin manuscripts did not use punctuation in the same way, so you should not think of the comma as part of the grammar itself. It is just there to help you read the sentence more easily.