Medica dicit sanitatem non statim redire, sed paulatim.

Because dicit introduces an indirect statement in Latin.

After verbs like say, think, know, and hear, Latin often uses:

• accusative subject
• • infinitive verb

So instead of saying The doctor says that health returns, Latin says, literally:

• The doctor says health to return

That is why sanitas becomes sanitatem. It is the subject of the infinitive redire, and in this construction that subject goes into the accusative.

For the same reason: this is an indirect statement.

With dicit, Latin does not normally use a separate word for that plus a finite verb, as English does. Instead it uses:

• sanitatem = the subject of the reported statement, in the accusative
• redire = the reported verb, in the infinitive

So:

• sanitas redit = health returns
• medica dicit sanitatem redire = the doctor says that health returns

There is no separate Latin word here for that.

English says:

• The doctor says that health does not return immediately

Latin instead uses the accusative-and-infinitive construction:

• medica dicit sanitatem non statim redire

So the idea of that is built into the grammar of sanitatem ... redire.

Medica is the feminine form of medicus. Here it means a female doctor or female physician.

It is:

• nominative singular
• the subject of dicit

So medica dicit = the female doctor says.

If the doctor were male, you would usually expect medicus dicit.

Redire means to return or to come back.

It comes from:

• re- = back
• ire = to go

So literally it is something like to go back.

Its principal parts are commonly given as:

• redeo, redire, redii/redivi, reditum

In this sentence, redire is the present active infinitive: to return.

They are both adverbs.

• statim = immediately, at once
• paulatim = gradually, little by little

They modify redire:

• non statim redire = not return immediately
• sed paulatim = but gradually

So they describe how the return of health happens.

This is a very natural contrast in Latin:

• non ... sed ... = not ... but ...

Here the contrast is between two adverbs:

• not immediately
• but gradually

So the sentence is setting up a correction or contrast: health does return, but not right away; it returns little by little.

In sense, it mainly negates statim.

The idea is not health does not return at all, but rather:

• health does not return immediately
• it returns gradually instead

So the whole phrase means: not immediately, but gradually.

Latin often places non right before the word or phrase it most directly affects, and here that is statim.

Because Latin, like English, can omit a repeated word when it is easy to understand.

The full idea is:

• sanitatem non statim redire, sed paulatim redire

But repeating redire is unnecessary. So Latin leaves it out after sed paulatim.

English does the same thing:

• Health returns not immediately, but gradually
• We do not have to say returns twice.

Yes. The sentence is perfectly natural.

Latin word order is more flexible than English word order because endings show grammatical function. Still, this sentence is arranged quite neatly:

• Medica = subject
• dicit = main verb
• sanitatem ... redire = indirect statement
• non statim, sed paulatim = contrasting adverbs

A very literal order would be:

• The female doctor says health not immediately to return, but gradually.

In smoother English, of course:

• The doctor says that health does not return immediately, but gradually.

Yes, depending on context.

The noun sanitas, sanitatis basically means:

• health
• soundness
• sometimes recovery to health, depending on the situation

In this sentence, since it is something that returns gradually, English may naturally express it as either:

• health
• recovery
• good health

The Latin word itself is still sanitas.

Sanitatem is:

• accusative singular
• from sanitas, sanitatis
• a third-declension noun
• feminine

Its ending -em is a common accusative singular ending for many third-declension nouns.

Here are two forms:

• sanitas = nominative singular
• sanitatem = accusative singular

In this sentence, the accusative is required because of the indirect statement.

Yes. Dicit is present active indicative, third person singular, from dicere.

It means:

• he says
• she says
• is saying

Because the subject is medica, the natural translation is she says or the doctor says.

So the main clause is simply:

• Medica dicit = The doctor says

Sometimes Latin can use quod-clauses, especially in later Latin or in certain contexts. But in standard classical prose, after verbs of saying and thinking, the usual construction is the accusative + infinitive.

So here the most expected form is exactly what you see:

• medica dicit sanitatem redire

That is one of the most important patterns for a learner to recognize in Latin.

The biggest point is the indirect statement after dicit.

A good way to spot it is:

1. Find the verb of saying/thinking: dicit
2. Look for an accusative noun: sanitatem
3. Look for an infinitive: redire

That combination tells you:

• sanitatem redire = that health returns

Then add the modifiers:

• non statim, sed paulatim = not immediately, but gradually

So the sentence is an excellent example of a very common Latin construction.