Se vocês discordarem da decisão, podem falar com o diretor.

Because after se Portuguese often uses the future subjunctive when talking about a possible future condition.

So:

• Se vocês discordarem da decisão... = If you disagree with the decision...
• Se vocês discordam da decisão... sounds more like if you disagree with the decision as a present/general fact, not as a future possibility.

In this sentence, the speaker means if that situation happens, so discordarem is the natural choice.

In this sentence, it is functioning as the future subjunctive.

That can be confusing because for many verbs, the future subjunctive and the personal infinitive look exactly the same:

• discordarem
• falarem
• comerem

So the form itself is identical, but the job it is doing in the sentence is different. After se in a future condition, it is read as future subjunctive.

In modern Portuguese, vocês takes 3rd-person plural verb forms, not 2nd-person plural ones.

So you get:

• vocês discordarem
• vocês podem

not:

• vocês discordardes
• vocês podeis

Those older 2nd-person plural forms belong to vós, which is not normally used in everyday modern European Portuguese.

Yes. Portuguese often drops subject pronouns when the verb already makes the subject clear.

So this is also natural:

• Se discordarem da decisão, podem falar com o diretor.

Adding vocês gives a little more emphasis or clarity, but it is not required.

Yes, vocês is normal and widely understood in Portugal.

A useful nuance is this:

• singular você can sometimes sound blunt or awkward in European Portuguese, depending on context
• plural vocês is usually much less problematic

So vocês in this sentence is perfectly standard. In some situations, though, Portuguese speakers may simply omit the pronoun or use another form of address, especially in more formal contexts.

Because the verb discordar normally takes the preposition de.

So you say:

• discordar de algo
• discordar de alguém
• discordar da decisão

Here, de + a decisão contracts to da decisão.

Some useful contractions:

• de + o = do
• de + a = da
• de + os = dos
• de + as = das

So discordar da decisão literally follows the pattern to disagree with/from the decision, even though in English we say disagree with the decision.

It is poder + infinitive, a very common structure in Portuguese.

• podem = you can / you may
• falar = to speak / to talk

Together, podem falar means you can speak or you may speak.

In this sentence, it gives an option or permission:

• If you disagree with the decision, you can speak with the director.

Because falar com alguém is the normal way to say to speak with / talk to someone.

So:

• falar com o diretor = talk to / speak with the director

You may also hear falar ao diretor, which can sound a bit more formal or a bit more one-directional. But falar com is very natural when the idea is having a conversation.

What you cannot say here is:

• falar o diretor

That would be incorrect for this meaning.

Portuguese uses definite articles more often than English.

So o diretor means the director, referring to a specific director known in the situation.

Even when English might sometimes leave the article out in certain contexts, Portuguese often keeps it:

• o diretor
• a professora
• o médico

Here, the article helps show that we mean the particular director connected to the decision or institution.

Because the sentence starts with a conditional clause:

• Se vocês discordarem da decisão

and then moves to the main clause:

• podem falar com o diretor

Portuguese normally separates that opening if-clause from the main clause with a comma. English often does the same:

• If you disagree with the decision, you can speak with the director.