Medica dicit dolorem in pectore non gravem esse.

Medica is the subject of the sentence, so it is in the nominative singular.

It is the feminine form, so it means female doctor (or woman doctor). If the doctor were male, you would expect medicus instead.

So:

• medica = nominative singular
• function = subject of dicit

This is one of the most important features of the sentence.

After a verb like dicit (says), Latin often uses indirect statement, also called the accusative-and-infinitive construction.

In a direct statement, you would have:

• dolor in pectore non gravis est = the pain in the chest is not serious

But after dicit, Latin changes that to indirect statement:

• dolorem in pectore non gravem esse

So:

• dolor → dolorem
• est → esse

That is why dolorem is accusative.

Because this is an indirect statement after dicit.

In English, we often say:

• The doctor says that the pain is not serious.

Latin usually does not use a word like that here. Instead, it uses:

• accusative noun
  • infinitive

So esse is the infinitive of sum (to be), and it corresponds to English is in reported speech.

A helpful way to think of it is:

• direct: dolor ... non gravis est
• reported after dicit: dolorem ... non gravem esse

Because gravem agrees with dolorem.

The word gravis, grave means serious, heavy, or severe, depending on context. Here it is describing dolorem, so it must match it in:

• gender: masculine
• number: singular
• case: accusative

Since dolorem is masculine singular accusative, the adjective must also be masculine singular accusative:

• gravis = nominative masculine/feminine singular
• grave = nominative/accusative neuter singular
• gravem = accusative masculine/feminine singular

So gravem is the correct form.

Because Latin word order is much more flexible than English word order.

English usually prefers words that belong together to stay close together. Latin can separate them without causing confusion, because the endings show the relationships.

Here, dolorem and gravem still clearly go together because their forms make the grammar clear.

So even though they are separated by in pectore and non, the meaning is still easy for a Latin reader to understand.

Because Latin commonly expresses reported statements differently from English.

English often uses:

• says that ...

Latin often uses:

• accusative + infinitive

So instead of something like dicit quod..., classical Latin normally prefers:

• dicit dolorem in pectore non gravem esse

In other words, the idea of English that is built into the construction itself.

Because in can take different cases depending on the meaning.

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

Here the meaning is location: the pain is in the chest, not moving into it. So Latin uses the ablative:

• in pectore = in the chest

Pectore is the ablative singular of pectus, pectoris.

It tells you where the pain is located.

So dolorem in pectore means:

• the pain in the chest
• or pain in the chest

Grammatically, it is a prepositional phrase modifying dolorem.

Non negates gravem, and therefore the statement that the pain is serious.

So the idea is:

• the pain is not serious
• the pain is not severe

Its position right before gravem makes the negation especially clear.

Yes, in a broad sense.

After dicit, the entire indirect statement functions as what is being said:

• medica dicit = the doctor says
• dolorem in pectore non gravem esse = that the pain in the chest is not serious

So the whole accusative-and-infinitive phrase is the content of the saying.

More specifically:

• dolorem is the subject of esse within the indirect statement
• the whole clause is what dicit introduces

Yes. Latin word order is flexible, and you could rearrange this sentence in other ways without changing the basic meaning.

For example, Latin could also say:

• Medica dolorem in pectore non gravem esse dicit.

That may feel more natural to an English speaker because dicit and its content stay closer together.

The given order is still perfectly normal Latin. Often Latin places the main verb early, and the infinitive esse commonly comes near the end of the reported statement.

It would be:

• Dolor in pectore non gravis est.

Then, after medica dicit, it becomes:

• Medica dicit dolorem in pectore non gravem esse.

This is a very useful transformation to know:

• nominative subject → accusative
• finite verb → infinitive

So:

• dolor → dolorem
• gravis → gravem
• est → esse