A Júlia ainda não chegou à reunião online.

Júlia hasn’t arrived at the online meeting yet.

Breakdown of A Júlia ainda não chegou à reunião online.

• chegar: to arrive
• a reunião: the meeting
• à: to the
• online: online
• ainda não: not yet
• Júlia: Júlia

Questions & Answers about A Júlia ainda não chegou à reunião online.

Why is there A before Júlia? Do you have to use an article with people’s names?

In Brazilian Portuguese, it’s common (and very natural in many regions) to use the definite article o/a before a person’s first name: a Júlia, o Pedro.
It’s not strictly mandatory everywhere, but it’s extremely frequent in speech and also appears in writing, especially informal or semi-formal contexts. It usually doesn’t change the meaning; it just sounds more idiomatic in Brazil.

Why is it A Júlia (feminine) and not O Júlia?

The article agrees with the person’s grammatical gender. Júlia is a female name, so it takes a (feminine singular). A male name would take o: O João ainda não chegou...

What does ainda não mean here, and why is it placed before the verb?

ainda não means not yet. In Portuguese it commonly goes before the main verb:

• A Júlia ainda não chegou = Júlia hasn’t arrived yet.
  You can sometimes move ainda for emphasis, but ainda não + verb is the most neutral, common pattern.

Could I say não chegou ainda instead?

Yes. A Júlia não chegou ainda is also correct and common.
A typical difference is emphasis/rhythm:

• ainda não chegou often highlights not yet early (expectation of arrival).
• não chegou ainda can feel slightly more conversational, with ainda added as an afterthought.
  Both are natural in Brazil.

Why is the verb chegou and not something like está chegando?

chegou is the pretérito perfeito (simple past in form; often like has arrived/arrived in meaning). It states the result: she has not arrived up to now.
está chegando would mean she is arriving / is on her way in the act of arriving, suggesting the process is happening right now. The sentence you have is about the current status: she still hasn’t arrived.

Is chegar normally used with the preposition a? Could it be em?

With the meaning to arrive (at a destination), chegar commonly uses a in standard usage: chegar a algum lugar.
In Brazil, people also often say chegar em in everyday speech: chegar na reunião, chegar em casa. It’s very common conversationally, but chegar a is more formal/standard, especially in careful writing.

What is à and why does it have that accent?

à is a contraction of a (preposition) + a (feminine singular definite article):

• chegar a
  • a reunião → chegar à reunião
    The grave accent (called crase) marks this contraction. It’s basically signaling a + a = à.

How do I know it’s à reunião (with crase) and not just a reunião?

A quick way is: if the destination noun normally takes the article a (a reunião, a escola, a festa), and the verb/preposition requires a, then you get à.
Here:

• noun: a reunião (it uses a)
• arrival uses: chegar a
  So: chegar à reunião.
  If the noun didn’t take an article (for example many city names), you typically wouldn’t use à.

Why is it reunião online and not reunião onlinea or something that agrees in gender?

online in Portuguese is typically invariable (it doesn’t change for gender/number). It works like an adjective placed after the noun:

• reunião online (online meeting)
• aulas online (online classes)

Is the word order reunião online fixed? Could it be online reunião?

The most natural order is noun + adjective: reunião online.
Putting online before the noun is unusual in Portuguese and would sound non-native in most contexts. (Portuguese can place some adjectives before nouns, but online generally stays after.)

Why isn’t there a word for to in the sentence? In English we say arrive to/at.

Portuguese expresses that idea using prepositions that attach directly to the verb phrase. Here, chegar + a covers the arrive at/to meaning, and it merges with the article to become à: chegou à reunião.

Could I omit A and just say Júlia ainda não chegou...?

Yes, it’s grammatically correct. Whether it sounds natural depends on region and style. In many parts of Brazil, A Júlia... is more typical in everyday speech. Omitting the article can sound slightly more formal or more like some European Portuguese patterns, but it’s still fine in Brazil.

Does this sentence imply she is late, or just that she hasn’t joined yet?

By itself, it only states the current fact: she still hasn’t arrived/joined the online meeting.
Whether she’s “late” depends on context (e.g., if the meeting already started). In online-meeting contexts, chegar can naturally mean to show up / join.