I believe in diversity – until it comes to languages, when I have some doubts. Nevertheless, the challenge can be a lot of fun.
Alicia Pons teaches classes in the big room on a Friday night. (Technically it's Ana Maria Schapira's class, but she's away on tour: she visits Europe to teach at least once every year but, sadly, has never been invited to the UK.) Alicia Pons is lively and energetic, quick on her feet. The classes are a lot of fun, and if you understand castellano well, you'd find them even more fun, because she enjoys banter, word-play, repartee. It's a lively atmosphere. She begins either with walking exercises, or with what Tete Rusconi calls (if I remember right) 'un poco de boogie-woogie': she came to tango via Tete from classical dance, and slow jive is a good warm-up to tango. & you don't have to understand the intermittent banter to enjoy it.
Taking tango classes in the language it grew up in is a challenge. Of course I'd never claim that classes in English are less effective. It's just that English alone never gives you the experience of being on a dance floor in a big room in a far-off country in the company of the descendants of the people who developed the music and the dance in the first place. & there's a lot of warmth and friendship, and a lot of dancing, in these classes.
It's not difficult to take tango classes in Spanish, but obviously you need basic language skills, and a bit of specialist vocabulary, like the names of body parts: shoulders, chest, knees, feet, as well as obvious words like forwards, back, to the side, turn. But mainly you need to watch very carefully. Dance is body language, and moreover the Spanish/Italian culture uses gestures a lot, so you can get more than the gist just by looking. Understanding is always easier than speaking, but when it comes to social dancing you need to be capable of brief conversations.