Laurus alta in horto stat, et avia folia eius laudat.

Latin normally does not use articles the way English does. So:

• laurus can mean laurel, a laurel tree, or the laurel tree
• horto can mean garden or the garden

The context tells you how to understand it in English.

Because adjectives in Latin must agree with the noun they describe in:

• gender
• number
• case

Here alta describes laurus, so it matches it. Since laurus is feminine nominative singular, the adjective must also be feminine nominative singular: alta.

Because Latin grammatical gender is not the same thing as biological sex.

A noun can be:

• masculine
• feminine
• neuter

even if the thing itself is not male or female. Laurus is simply a feminine noun. In fact, many Latin names of trees are feminine.

So alta is feminine because it agrees with the grammatical gender of laurus, not because the tree is literally female.

Because Latin uses different cases after in depending on the meaning:

• in + ablative = in/on a place, with no movement
• in + accusative = into a place, showing motion toward it

Here the tree is already standing in the garden: stat. That is location, not motion. So Latin uses in horto.

Horto is ablative singular of hortus.

You know this because:

• the preposition in takes the ablative when it means location
• the meaning here is in the garden, not into the garden

So in horto = in the garden.

A few clues help:

• avia is nominative singular, the usual case for a subject
• laudat is third person singular, so it needs a singular subject
• folia is plural, so it cannot be the subject of laudat here
• folia makes sense as the thing being praised, so it is the direct object

So in the second clause:

• avia = subject
• folia eius = object

Because folia is a neuter plural form.

In Latin, neuter nouns often have:

• singular nominative/accusative in -um
• plural nominative/accusative in -a

So:

• folium = leaf
• folia = leaves

Here folia is the accusative plural, the direct object of laudat.

Eius means his / her / its.

Here it means its, referring back to laurus: the grandmother praises its leaves.

Latin uses suus, sua, suum only when the possessor is the subject of the same clause. But in the second clause, the subject is avia, not laurus. So:

• eius = belonging to someone/something else
• suus = belonging to the subject

So folia eius is correct because the leaves belong to the laurel tree, not to the grandmother.

Because Latin verbs agree with the subject, not with the object.

Here:

• avia is the subject, and it is singular
• folia is the object, and it is plural

So the verb is singular: laudat = she praises / praises.

Stat is more specific and vivid than est.

• est = is
• stat = stands, is standing

For a tree, stat is very natural, because a tree stands upright in a place. So laurus alta in horto stat gives a clearer picture than simply using est.

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

For example, you could also have:

• In horto laurus alta stat
• Laurus in horto alta stat
• Et avia eius folia laudat

These can all mean essentially the same thing, though the emphasis may change.

The given order is perfectly natural, and it presents the sentence clearly:

• first the tree and where it is
• then the grandmother and what she praises