No meio da reunião online, a internet caiu.

Literally, no meio da reunião online means in the middle of the online meeting.

It is built like this:

• no = contraction of em + o
• meio = middle
• da = contraction of de + a

The fixed expression is no meio de = in the middle of.

When the next noun uses the feminine article a, de + a becomes da:

• no meio da reunião
• base structure: no meio de a reunião
• natural contracted form: no meio da reunião

So the whole chunk works as one expression: no meio da... = in the middle of...

Because Portuguese usually uses an article before many nouns, much more often than English does.

Here, reunião is feminine, so it often appears as a reunião.
Since the expression is no meio de, the de combines with a:

• de + a = da

So:

• no meio da reunião = in the middle of the meeting

Saying no meio de reunião is not the normal choice here. The version with the article, no meio da reunião, sounds natural and complete.

Yes. In Brazilian Portuguese, internet is normally treated as a feminine noun:

• a internet
• a internet caiu
• a internet está lenta

So a internet caiu literally means the internet fell, but naturally it means the internet went down or the connection dropped.

More generally, Portuguese often uses definite articles where English does not. English says simply internet in many cases, but Portuguese commonly says a internet.

Because cair is often used idiomatically in Portuguese for systems, connections, calls, websites, and electricity when they suddenly stop working.

Examples:

• A internet caiu. = The internet went down.
• A ligação caiu. = The call dropped.
• O sistema caiu. = The system went down.
• A energia caiu. = The power went out.
  In some contexts, people also say faltou energia.

So although cair literally means to fall, in everyday Portuguese it often has this extended meaning of dropping, failing, or going down.

Caiu is the preterite form of cair for ele/ela/você.

• infinitive: cair
• preterite: caiu
• meaning here: went down / dropped

In this sentence, the preterite is used because it describes a completed event that happened at a specific moment:

• No meio da reunião online, a internet caiu.

That feels like: one thing was happening, and then suddenly this event occurred.

Because caiu presents the event as a single completed interruption.

• caiu = went down, dropped
• caía = was going down / used to go down

In this sentence, the idea is that the meeting was in progress and then, at one moment, the internet dropped. That is exactly the kind of event Portuguese usually expresses with the preterite:

• a internet caiu

If you said a internet caía, it would sound like a repeated past habit or an ongoing background situation, which does not fit as well here.

The comma separates the opening time-expression from the main clause:

• No meio da reunião online, a internet caiu.

The first part sets the scene, and the second part gives the main event.

In Portuguese, a comma after a longer introductory phrase like this is very common and natural. It helps readability. Without the comma, the sentence may still be understood, but the comma is the better written choice here.

Yes, absolutely.

Both are natural:

• No meio da reunião online, a internet caiu.
• A internet caiu no meio da reunião online.

The difference is mainly focus:

• No meio da reunião online, a internet caiu.
  This highlights the timing first.
• A internet caiu no meio da reunião online.
  This starts with the main event.

Both mean essentially the same thing.

Online is very natural in Brazilian Portuguese, especially in everyday speech.

So reunião online sounds completely normal.

You could also hear:

• reunião virtual
• reunião por vídeo
• videoconferência

But the nuances are a little different:

• reunião online = common, modern, everyday
• reunião virtual = also common, slightly more formal or technical in some contexts
• videoconferência = more specific and more formal

For casual, natural Brazilian Portuguese, reunião online is a very good choice.

A helpful approximate pronunciation is heh-oo-nee-OWN, but with Portuguese sounds, not English ones.

A few important points:

• reu is said smoothly, almost like reh-oo
• ni sounds like nee
• ão is nasal, which is one of the trickiest sounds for English speakers

The stress is on the last syllable:

• reu-ni-ÃO

That final ão is very common in Portuguese, and it is nasal, so air resonates through the nose as well as the mouth.

It is pronounced in two syllables:

• ca-iu

A rough approximation is kah-YOO, but lightly and quickly.

Important point: the stress falls on the second part:

• ca-IU

Learners sometimes want to compress it too much, but it is better to hear it as two clear vowel parts.

Not exactly.

• durante a reunião = during the meeting
• no meio da reunião = in the middle of the meeting

Durante is broader and more neutral.
No meio de gives a stronger sense that something happened while the event was underway, often interrupting it.

So in this sentence:

• No meio da reunião online, a internet caiu.

there is a clear feeling of interruption at an inconvenient moment. That is why it works especially well here.

Yes, and it is also very natural.

There is a small nuance:

• a internet caiu = the internet went down
• a conexão caiu = the connection dropped

In everyday use, both can work in similar situations. But:

• internet can sound broader
• conexão can sound slightly more specific to the active connection at that moment

Other common alternatives are:

• A internet caiu.
• A conexão caiu.
• Fiquei sem internet. = I lost internet / I had no internet.
• A ligação caiu. = The call dropped.

Because Portuguese often places time or context information at the beginning of the sentence very naturally.

So:

• No meio da reunião online, a internet caiu.

starts by setting the scene, then gives the main event.

English can do the same:

• In the middle of the online meeting, the internet went down.

So the structure is not strange in Portuguese. In fact, it is very natural and common.