"Speak" is "sprechen." Also, if you're not using a modal or auxiliary verb (like "can," "may," "want to"), you need to put "zu" before the infinitive and add a comma: "Wir lernen zu sprechen."
I'm not sure you need a comma there if there's no object for the verb "sprechen". I could be wrong...
You're right, thanks. I've deleted it. The comma isn't wrong, but most people wouldn't put it there. It's only necessary for longer "zu" clauses--like you said, it's usually omitted if there's just a verb or a verb and an object.
My first language (Slovenian), also uses tongue for language, so you say "my mother tongue is Slovenian".
And in Spahish: lengua can also mean language even that we have a word for that also: lenguaje.
It reminds me with arabic. in arabic, tongue means a language as well.
my native language also use it for both senses, but in English sound strange...
That would be wir lernen Redensarten. "Idiom" in English does not mean "language". It means "expressão idiomática".
Some languages use the same word for "language" and "tongue", for instance "mother tongue".