Αμφιβάλλω αν θα φτάσουμε στην ώρα μας με τόση κίνηση.

Αμφιβάλλω means I doubt. It is:

• 1st person singular
• present tense
• from the verb αμφιβάλλω

So the speaker is saying I doubt...

Here αν introduces an indirect yes/no clause, so it means whether / if in the sense of uncertainty.

So:

• Αμφιβάλλω αν θα φτάσουμε... = I doubt whether / if we will arrive...

This is not a conditional if like If it rains, we'll stay home.
It is closer to I’m not sure whether... or I doubt that...

In Modern Greek, the simple future is usually formed with:

• θα
  • perfective non-past form

So:

• θα φτάσουμε = we will arrive / we will get there

The form φτάσουμε comes from φτάνω (to arrive, to reach).
Even though this form looks like what learners often meet as a subjunctive-type form, after θα it simply makes the future.

Because Greek usually does not need subject pronouns unless there is emphasis.

The ending in φτάσουμε already tells you the subject is we.

So:

• φτάσουμε = we arrive / we will arrive

If you said εμείς θα φτάσουμε, that would add emphasis, something like we will arrive.

στην is the contraction of:

• σε
  • την → στην

Here it means at / to the.

So:

• στην ώρα μας literally = at our time

This contraction is extremely common in everyday Greek.

στην ώρα μας is an idiomatic way to say on time.

Literally it looks like:

• στην ώρα = at the time
• μας = our

So the full idea is at our proper/scheduled time.

The μας refers to our time, meaning the time that is appropriate for us, expected for us, or scheduled for us. In natural English, we usually do not say our time here, but Greek does.

Because the preposition σε takes the accusative in Modern Greek.

So:

• η ώρα = the time (nominative)
• την ώρα = the time (accusative)

Since the phrase is σε την ώρα → στην ώρα, you get the accusative form ώρα with την.

Literally, it means with so much traffic.

Breakdown:

• με = with
• τόση = so much / this much
• κίνηση = movement, traffic

In this sentence, κίνηση clearly means traffic.
So the phrase explains the reason for the speaker’s doubt: because there is so much traffic.

Because τόση has to agree with κίνηση.

• κίνηση is feminine singular
• so the matching form is τόση

This is adjective-like agreement:

• masculine: τόσος
• feminine: τόση
• neuter: τόσο

Since κίνηση is feminine, Greek uses τόση.

No, Greek word order is often more flexible than English word order.

The sentence as written is perfectly natural:

• Αμφιβάλλω αν θα φτάσουμε στην ώρα μας με τόση κίνηση.

But Greek could also move parts around for emphasis, for example:

• Με τόση κίνηση, αμφιβάλλω αν θα φτάσουμε στην ώρα μας.

The basic meaning stays the same, but the emphasis changes slightly. Putting με τόση κίνηση first highlights the traffic more strongly.

As a learner, the safest and most useful pattern to learn is:

• αμφιβάλλω αν...

This is very common when you mean I doubt whether / if...

You may sometimes encounter ότι after αμφιβάλλω, especially in meanings closer to I doubt that..., but αν is the clearest and most straightforward choice in a sentence like this.

So for this example, Αμφιβάλλω αν θα φτάσουμε... is exactly the pattern you should be comfortable with first.