Η παιδίατρος μας θύμισε ότι το επόμενο εμβόλιο είναι τον επόμενο μήνα.

Here it means us: μας θύμισε = reminded us.

This can confuse learners because μας can also mean our in other contexts. For example:

• η παιδίατρός μας = our pediatrician
• μας θύμισε = reminded us

In standard writing, if μας is possessive after παιδίατρος, you would usually see an extra accent: η παιδίατρός μας. In your sentence, the natural reading is The pediatrician reminded us...

Because some Greek nouns ending in -ος can be either masculine or feminine, especially profession words.

So you get:

• ο παιδίατρος = the male pediatrician
• η παιδίατρος = the female pediatrician

The article tells you the gender here, not the ending by itself.

Θύμισε is the aorist (simple past) of θυμίζω, and here it is 3rd person singular:

• θυμίζω = I remind
• θύμισε = he/she reminded

So Η παιδίατρος μας θύμισε means The pediatrician reminded us.

If it were imperfect, it would be θύμιζε, meaning something more like was reminding or used to remind.

No. This is a very common mix-up.

• θυμίζω = to remind
• θυμάμαι = to remember

So:

• μας θύμισε = she reminded us
• θυμήθηκε = she remembered

Greek uses two different verbs, just like English does.

Ότι introduces a content clause and means that:

• Η παιδίατρος μας θύμισε ότι...
• The pediatrician reminded us that...

It connects the main clause to the information being reminded.

Also, learners often confuse ότι with ό,τι:

• ότι = that
• ό,τι = whatever / anything that

So in this sentence, it is definitely ότι = that.

Yes, very often.

You could also say:

• Η παιδίατρος μας θύμισε πως το επόμενο εμβόλιο είναι τον επόμενο μήνα.

In this kind of sentence, ότι and πως both commonly mean that.
Ότι is often felt as a bit more neutral or formal, while πως is very common in everyday speech too.

Because εμβόλιο is a neuter singular noun, so the article and adjective must agree with it:

• το = neuter singular the
• επόμενο = neuter singular next
• εμβόλιο = vaccine

So:

• το επόμενο εμβόλιο = the next vaccine / the next shot

Greek adjectives must match the noun in gender, number, and case.

No, because τον επόμενο μήνα is not a predicate noun. It is a time expression meaning next month.

Greek often uses the accusative for expressions of time:

• τον επόμενο μήνα = next month
• την Παρασκευή = on Friday
• την άλλη εβδομάδα = next week

So even though it comes after είναι, it is not functioning like he is a doctor. It is functioning adverbially: it tells you when.

Yes, it is understandable and natural in everyday speech, but it is a bit elliptical.

Literally, Greek says something like:

• the next vaccine is next month

What is really meant is:

• the next vaccine is scheduled for next month
• the next vaccine is due next month

Greek often leaves out words that are obvious from context. A more explicit version might be:

• Το επόμενο εμβόλιο είναι προγραμματισμένο για τον επόμενο μήνα.

But the shorter version is very normal in conversation.

Yes. Greek word order is more flexible than English word order.

The sentence you have is a neutral, natural order:

• Η παιδίατρος μας θύμισε ότι...

But you could also say:

• Μας θύμισε η παιδίατρος ότι...

This puts a little more focus on μας θύμισε or sounds more conversational in some contexts.

What usually matters most is the endings and the role of each word, not only its position.

A rough English-style guide:

• παιδίατρος ≈ peh-DHEE-ah-tros
• θύμισε ≈ THEE-mi-se
• εμβόλιο ≈ em-VOH-lee-o
• επόμενο ≈ eh-POH-me-no
• μήνα ≈ MEE-na

A few useful sound notes:

• αι sounds like e in met
• ει and η sound like ee
• θ sounds like th in think
• δ in modern Greek sounds like th in this

So παιδίατρος does not sound like it looks to an English speaker at first glance.