Ambulatio in horto corpori salubris est.

Because ambulatio is in the nominative singular, which is the case normally used for the subject.

• ambulatio = a walk / walking
• It is a third-declension feminine noun
• The verb est is singular, so the singular subject ambulatio fits perfectly

So the basic structure is:

• ambulatio = subject
• salubris = predicate adjective describing the subject
• est = is

It can be understood as either walking or a walk, depending on how naturally you want to translate it into English.

Grammatically, ambulatio is a noun, not a verb. It comes from the idea of walking, but Latin expresses it here as a thing or activity:

• ambulatio = a walk
• or more loosely, walking

So English might say:

• A walk in the garden is healthy for the body
• Walking in the garden is healthy for the body

Both reflect the Latin well.

Because in takes different cases depending on the meaning:

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

Here, in horto means in the garden, so it answers where?, not where to?

• horto is ablative singular
• If the sentence meant into the garden, it would be in hortum

So:

• ambulatio in horto = a walk in the garden
• ambulatio in hortum would not fit the intended meaning

Because the adjective salubris can take the dative of the person or thing affected, especially in the sense of healthy for, beneficial to, or good for.

So:

• corpori = for the body / to the body
• it is the dative singular of corpus, corporis (body)

This is a very common idea in Latin: some adjectives naturally go with the dative.

So corpori salubris est means:

• is healthy for the body
• is beneficial to the body

Not every English for is translated by the dative, but this is a standard Latin pattern.

Because corpus would be the nominative or accusative singular, and that would not fit the grammar here.

The sentence does not mean:

• the walk is the body
• or the walk healthy body is

Instead, the idea is that the walk is beneficial to the body, so Latin uses the dative:

• corpus = the body as subject or direct object
• corpori = to/for the body

That is why corpori is the correct form.

Salubris is nominative singular feminine here, agreeing with ambulatio.

Why feminine?

• ambulatio is a feminine noun
• predicate adjectives in Latin agree with the subject in gender, number, and case

So:

• ambulatio = feminine nominative singular
• salubris = feminine nominative singular

Even though corpori comes right before it, salubris does not agree with corpori. It agrees with ambulatio.

You know from both meaning and grammar.

1. Grammar

Salubris is nominative singular here, matching ambulatio.

But corpori is dative singular, so salubris is not agreeing with it.

2. Sentence pattern

The structure is:

• Ambulatio = subject
• corpori = dative, for the body
• salubris est = is healthy

So the sense is:

• A walk in the garden is healthy for the body

not

• A walk in the garden is a healthy body

Because Classical Latin has no definite article like English the, and no indefinite article like a/an either.

So:

• horto can mean garden or the garden
• corpori can mean body or the body
• ambulatio can mean a walk, the walk, or just walking

The exact English article depends on context and natural translation.

That is completely normal in Latin.

The word order is fairly natural Latin, but Latin word order is much more flexible than English word order.

This sentence is arranged as:

• Ambulatio — subject first
• in horto — prepositional phrase
• corpori — dative
• salubris est — adjective + verb at the end

A Latin writer could rearrange the words without changing the basic meaning, for example:

• Ambulatio corpori in horto salubris est
• In horto ambulatio corpori salubris est

The endings show the grammatical roles, so word order can be used for emphasis rather than strict grammar.

Yes. In fact, a walk in the garden is the more literal rendering because ambulatio is a noun.

• ambulare = to walk
• ambulatio = a walking / a walk

But English often prefers walking in the garden because it sounds smoother and more idiomatic.

So both are good, depending on your translation style:

• A walk in the garden is healthy for the body
• Walking in the garden is healthy for the body

Yes. Salubris often means:

• health-giving
• wholesome
• healthy
• beneficial

It can describe something that promotes health, not just something that possesses health.

So in this sentence, salubris means something like:

• good for one’s health
• healthful
• beneficial

That is why it fits so well with corpori.

You would usually look them up like this:

• ambulatio, ambulationis f. = walk, walking
• in = in, on; into, onto depending on case
• hortus, horti m. = garden
• corpus, corporis n. = body
• salubris, salubre = healthy, healthful, beneficial
• sum, esse, fui = to be

That helps explain the forms in the sentence:

• ambulatio from ambulatio, ambulationis
• horto from hortus, horti
• corpori from corpus, corporis
• est from sum, esse

Here is a full parsing:

• Ambulatio: noun, nominative singular feminine
  subject; a walk / walking

• in: preposition taking the ablative here
  means in

• horto: noun, ablative singular masculine
  object of in; in the garden

• corpori: noun, dative singular neuter
  for the body / to the body

• salubris: adjective, nominative singular feminine
  predicate adjective agreeing with ambulatio

• est: verb, 3rd person singular present active indicative of sum
  is

So the grammar is very compact, but each word has a clear role.