Here are a few openers you can use in ANY bar or club in a Spanish speaking country. These are casual conversation starters you can use to get some small talk going. They work well for someone you are attracted to or if you just want to hang out with some locals.

What's the best national beer from this country?
¿Cual es la mejor cerveza nacional de este país?
¿kwahl ehs lah meh-hohr sehr-veh-sah nah-see-oh-nahl deh ehs-teh pah-EEs?

What are the local drinks from this country?
¿Cuales son los tragos nativos de este país?
¿kwah-lehs sohn lohs trah-gohs nah-tee-vohs deh ehs-teh pah-EEs?

What kind of drinks are popular here?
¿Qué tipo de tragos son populares aquí?
¿kEH tee-poh deh trah-gohs sohn poh-poo-lah-rehs ah-kEE?

These are good ways to start a conversation since you're showing interest in their country and what makes it different from others. Most people enjoy talking about things that are unique from their country.

Though these are ideal for bars and clubs you can use them anywhere to strike up a conversation.

To get the most out of your time spent traveling in other countries you want to mix with the locals. If you've met some cool people or have met someone you're attracted to and want to hang out with them you can ask them to get a drink with you:

Let's have a drink.
Vamos a tomar un trago.
vah-mohs ah toh-mahr oo-n trah-goh.

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