Hablé con mi cuñado.

Hablé is the first-person singular preterite of hablar.

• hablar = the infinitive, to speak / to talk
• hablé = I spoke / I talked

The preterite is used for a completed action in the past.

The accent mark in hablé shows where the stress goes: ha-BLÉ.

It is also important because it distinguishes hablé from other forms:

• hablé = I spoke
• hable = a different form, usually subjunctive or a formal command

So the accent is not optional here; it is part of the correct spelling.

They are both past tenses, but they are used differently.

• hablé = a completed past action
• hablaba = an ongoing, repeated, background, or habitual past action

So:

• Hablé con mi cuñado suggests a specific completed conversation.
• Hablaba con mi cuñado suggests I was talking to my brother-in-law or I used to talk to my brother-in-law, depending on context.

Yes. In Spain, he hablado con mi cuñado is very common, especially for something that happened:

• recently
• today
• in a time period still connected to the present

Very roughly:

• Hablé con mi cuñado = I spoke to my brother-in-law
• He hablado con mi cuñado = I have spoken / I’ve spoken to my brother-in-law

In many parts of Spain, the present perfect is used more often than in many Latin American varieties for recent past events.

Because hablar con is the usual way to say to talk with / to talk to someone in the sense of having a conversation.

• hablar con alguien = to talk with someone

You may also see hablar a alguien, but that usually sounds more like to speak to or address someone, often less like a two-way conversation.

So in this sentence, con is the most natural choice.

Because mi is the possessive adjective used before a noun:

• mi cuñado = my brother-in-law

Mío is usually used differently, often after a noun or on its own:

• un cuñado mío = a brother-in-law of mine
• Es mío = It is mine

So before cuñado, you need mi.

Usually, no.

Spanish often leaves out subject pronouns because the verb ending already shows who the subject is.

• hablé already means I spoke
• so yo is unnecessary unless you want emphasis or contrast

For example:

• Hablé con mi cuñado = neutral
• Yo hablé con mi cuñado, no mi hermana = emphasis or contrast

Cuñado can refer to more than one family relationship:

• your spouse’s brother
• your sibling’s husband

So it does not specify which type of brother-in-law unless the context makes it clear.

Also:

• cuñado = masculine
• cuñada = feminine

Cuñado is pronounced roughly like koo-NYA-do.

A more accurate pronunciation is approximately /kuˈɲaðo/ in standard Spanish.

A few points:

• ñ is like the ny sound in canyon, but as a single sound
• h in hablé is silent
• d in cuñado is usually soft between vowels in Spanish
• in Spain, the stress in cuñado falls on the -ña- syllable

So:

• hablé ≈ a-BLEH
• cuñado ≈ koo-NYA-dho / koo-NYA-do depending on accent

No. Hablé stays the same whether the speaker is male or female.

What can change is the family noun:

• mi cuñado = my brother-in-law
• mi cuñada = my sister-in-law

So the verb does not tell you the speaker’s gender.

This word order is the most normal and neutral:

• Hablé con mi cuñado

Spanish does allow some flexibility, but changes in word order usually add emphasis or sound more literary or marked.

For everyday speech, this is the natural order:

• verb + con
  • person

Yes. In Spain, cuñado can also be used informally as a slang term for a certain stereotype: someone who acts like a know-it-all, gives strong opinions, and speaks with too much confidence about things they may not really understand.

But in Hablé con mi cuñado, the default reading is the literal family meaning unless the context clearly suggests the slang sense.