Learn Hardcore Hungarian: Beszélünk a filmről.

Mi beszélünk a filmről. – We are talking about the film. (with explicit mi = we, for emphasis)
Beszélünk a filmről. – We are talking about the film. (neutral)

You only add mi (we) if you want to stress it, for example:

Mi beszélünk a filmről, nem ők. – We are talking about the film, not them.

Does beszélünk mean “we speak”, “we are speaking”, or “we will speak”?

Hungarian has only one present tense, which can correspond to several English tenses:

We speak / we talk (in general) – habitual action
We are talking (right now) – ongoing action
We will talk – near future, when the context makes it clear

So Beszélünk a filmről. can mean:

We are talking about the film (now).
or, with the right context,
We’ll talk about the film (later).

Context or extra words (like majd “later”, a time expression, etc.) clarify the time reference if needed:

Holnap beszélünk a filmről. – We’ll talk about the film tomorrow.

What does the a in a filmről mean?

A is the definite article in Hungarian, equivalent to English “the”.

a is used before words starting with a consonant:
a film, a könyv, a tanár
az is used before words starting with a vowel:
az alma, az ember

So a film = the film.

What does the ending -ről on filmről mean?

-ról / -ről is a case ending that usually means:

about
from the surface of (literal spatial meaning)

In this sentence it means “about”:

a filmről – about the film

Technically this is called the delative case.
The choice between -ról and -ről depends on vowel harmony:

after back vowels: usually -ról (pl. könyvről is an exception case due to mixed vowels)
after front vowels: usually -ről

Here, with film, the form is filmről.

Why is “about” attached to the noun (filmről) instead of being a separate word?

Hungarian often uses case endings on nouns where English would use prepositions.

English: about the film
Hungarian: a filmről (the film-about)

So instead of a separate word like “about”, Hungarian attaches a suffix (-ről) directly to the noun.
This is very common:

a könyvről – about the book
a városról – about the city
a munkáról – about the work / job

Could I say A filmről beszélünk instead? Does the word order change the meaning?

Yes, A filmről beszélünk is grammatically correct.

Beszélünk a filmről. – neutral, focus on the action “we are talking”.
A filmről beszélünk. – emphasizes the film as the topic: It’s the film we’re talking about (as opposed to something else).

In Hungarian, word order is used for emphasis and focus, rather than for showing subject–verb–object roles. Both sentences describe the same situation, but the highlighted part differs.

Why is there an article (a filmről) at all? Could I just say Beszélünk filmről?

Both are possible, but they’re not exactly the same:

Beszélünk a filmről. – We are talking about *the film.*
Refers to a specific, known film.
Beszélünk filmről. – We are talking about *a film / about films (in general).*
More indefinite or generic, without specifying which film.

Hungarian can drop the article to make the meaning more indefinite or more general, somewhat like the difference between “the film” and “a film / films” in English.

Is film singular or plural here? How would I say “about the films”?

In a filmről, film is singular: about the film.

To say “about the films”, you add the plural ending -k before the case ending:

a filmekről – about the films
film + ek + ről

So the order is:

noun stem: film
plural suffix: -ek
case ending: -ről

Why is it beszélünk and not beszéljük in this sentence?

Hungarian has two main conjugations: indefinite and definite.

Beszélünk a filmről. – We talk about the film.
Here, a filmről is not a direct object; it’s a case-marked complement (“about the film”), so the verb uses indefinite conjugation: beszélünk.
Beszéljük a filmet. – We are discussing the film / We talk the film over.
Here, a filmet is a direct object in the accusative (-t), so the verb uses definite conjugation: beszéljük.

So:

valamiről beszélni – to talk about something (indefinite verb form)
valamit megbeszélni / beszélni – to discuss something as a direct object (definite verb form)

What is the base dictionary form of beszélünk and how do other forms look?

The base (dictionary) form is beszél – “to speak, to talk”.

Some common present tense forms:

beszélek – I speak / I am speaking
beszélsz – you (sg. informal) speak
beszél – he / she / it speaks; you (formal sg.) speak
beszélünk – we speak
beszéltek – you (pl. informal) speak
beszélnek – they speak; you (formal pl.) speak

These are all indefinite forms (used when there is no definite direct object).

Is beszélünk ever used as a polite “you (plural)” form?

No. Beszélünk always means “we speak / we are speaking”.

The polite (formal) you in Hungarian uses 3rd person forms, not 1st person:

Beszél a filmről. – You (sir/ma’am) are talking about the film. (formal singular)
Beszélnek a filmről. – You (ladies and gentlemen) are talking about the film. (formal plural)

So:

beszélünk – we speak
beszél / beszélnek – formal you speak (sg. / pl.), depending on context

How is filmről pronounced? That lm + r cluster looks difficult.

Approximate pronunciation (in IPA): [ˈfilm.røːl].

film – like English film, but the l and m are clearly pronounced: [film]
Then directly ről: [røːl] (rolled or tapped r, long ő sound, then l)

There is a small break between film and ről, but no extra vowel: just film-ről.