Μάλλον σε συμφέρει να πάρεις το λεωφορείο σήμερα, όχι ταξί.

Here μάλλον most naturally means probably / most likely.

So Μάλλον σε συμφέρει... means something like It’s probably better for you... or You’d probably be better off...

In conversation, μάλλον can also soften advice, so it does not sound too direct.

Συμφέρει comes from συμφέρω and means to be advantageous, to be worth it, or to be better for someone from a practical or financial point of view.

So:

• με συμφέρει = it suits me / it’s worth it for me
• σε συμφέρει = it suits you / it’s worth it for you

In this sentence, σε συμφέρει means it’s better for you or it makes more sense for you.

Because συμφέρει uses the weak accusative pronoun in Modern Greek:

• με συμφέρει
• σε συμφέρει
• τον/τη συμφέρει
• μας συμφέρει

Even though English translates this as to me / to you, Greek does not use a dative form here. Modern Greek no longer has an ordinary productive dative case, so many meanings that English expresses with to are handled differently.

Not exactly in the English sense.

English often needs a dummy subject: It is better for you to take the bus.

Greek can simply say σε συμφέρει να πάρεις το λεωφορείο without adding a separate word for it. The idea to take the bus is expressed by the να clause:

• να πάρεις το λεωφορείο σήμερα

So the whole structure is roughly:

• Probably [it is advantageous to you] [to take the bus today]

After verbs and expressions like it’s good, it’s possible, it’s worth it, I want, I can, Greek normally uses να + subjunctive.

So:

• συμφέρει να... = it’s better / worth it to...

Examples:

• Με συμφέρει να περιμένω. = It’s better for me to wait.
• Σε συμφέρει να φύγεις τώρα. = It’s better for you to leave now.

Να πάρεις is the aorist subjunctive, and here it refers to one complete action: taking the bus today.

• να πάρεις = to take it once, as one event
• να παίρνεις = to be taking / to take regularly or repeatedly

Because the sentence is about a single decision today, να πάρεις is the natural choice.

If you said:

• Σε συμφέρει να παίρνεις το λεωφορείο

that would sound more like It’s better for you to take the bus regularly.

Because Greek, like English, often uses take with means of transport:

• παίρνω το λεωφορείο = take the bus
• παίρνω το τρένο = take the train
• παίρνω ταξί = take a taxi

You could also express the idea with go by:

• να πας με το λεωφορείο = to go by bus

But να πάρεις το λεωφορείο is completely normal and very common.

Greek often uses the article with common means of transport, especially in expressions like take the bus, take the train, and so on.

So το λεωφορείο here is very natural.

It does not have to mean one very specific bus. It can mean the bus as the normal transport option, much like English.

Because this is a short contrastive correction at the end:

• ..., όχι ταξί = ..., not a taxi / not the taxi option

Greek often leaves out words that are already understood. So instead of repeating the whole phrase, it just keeps the contrasting word.

That is why the bare noun ταξί sounds natural here.

Yes. The full idea would be something like:

• Μάλλον σε συμφέρει να πάρεις το λεωφορείο σήμερα, όχι να πάρεις ταξί.

But Greek usually avoids repeating the verb phrase when the meaning is obvious.

So όχι ταξί is an economical way to say:

• not a taxi
• not to take a taxi

Yes, but the nuance changes slightly.

• όχι ταξί = not a taxi, not the taxi option in general
• όχι το ταξί = not the taxi, possibly a more specific or more contrastive choice

In this sentence, όχι ταξί sounds more general and natural.

Yes, σήμερα can move because Greek word order is flexible.

The original sentence:

• Μάλλον σε συμφέρει να πάρεις το λεωφορείο σήμερα...

is very natural.

But you could also say:

• Μάλλον σήμερα σε συμφέρει να πάρεις το λεωφορείο.
• Μάλλον σε συμφέρει σήμερα να πάρεις το λεωφορείο.

The basic meaning stays the same. The difference is mainly one of emphasis.

Yes. Greek word order is much freer than English word order, especially when short pronouns like σε are involved.

For example, you may hear:

• Μάλλον σε συμφέρει να πάρεις το λεωφορείο σήμερα.
• Σε συμφέρει μάλλον να πάρεις το λεωφορείο σήμερα.
• Να πάρεις το λεωφορείο σήμερα μάλλον σε συμφέρει.

The first one is the most neutral. The others are possible, but they shift the emphasis.

Not exactly.

• συμφέρει = it is advantageous, worth it, better from a practical or financial point of view
• βολεύει = it is convenient

So in this sentence, σε συμφέρει suggests that taking the bus is the smarter choice, perhaps because it is cheaper, easier, or more sensible overall.

If you said σε βολεύει, the focus would be more on convenience than on advantage.