Today I'm in Oaxaca City, Mexico. Tomorrow I head to San Jerónimo Tlacochahuaya, about 20 km east of the city, where I'll spend the next month learning about Tlacochahuaya Zapotec. Since I'm here, I thought I'd answer the question posed to me by every rideshare driver: "You're a linguist? But, um, what do you do?"
When linguists study language, they're seeking to understand (a) what constraints there are on how languages work, and (b) how any particular language fits into those constraints.