Conversation Why does the woman say this:

W: My linguistics class is really getting good. Today the lecture was about the social aspects of language, like slang and accents, and stuff. But the thing that really intrigues me is something called a lingua franca.
M: Lingua franca?
W: Yeah. A lingua franca is sort of common language used by people who speak different languages. There are a lot of places in the world where everybody’s first language is different, and the people need to communicate with other groups, so everybody starts using one language for social or commercial relationships. That language that connects them all is a lingua franca.
M: That makes sense—kind of a universal business language. Where did the name "lingua franca" come from?
W: From the name of one of the first languages like that. It was like, in the Middle Ages, countries with ports on the Mediterranean needed a common trade language. So a new language sort of evolved. It was basically Italian,  mixed with French, Spanish, and other languages. It was called Lingua Franca,  which meant "Frankish language." After that,  "lingua franca" came to mean all languages used that way. So, any language can be a lingua franca if it connects tots of people who speak different languages. Most of the time lingua francas have been trade languages.
M: That means English is a lingua franca because English is an international business language.
W: Yeah. You’re right about that. English is definitely a lingua franca. In East Africa, Swahili is a lingua franca that’s understood in every marketplace. It’s because there are hundreds of tribes in East Africa, and each tribe speaks a different language. So most of the people there learn at least some Swahili as a second language.
M: interesting. And... uh... isn’t there some other language like that... I think it’s called something like "pigeon"... you know,  like the birds, like the pigeons that carry messages.
W: It’s not "pigeon" like the birds! It’s a different word—here,  let me show you—it has the same pronunciation,  but a different spelling. A "pidgin" is a type of language. It’s a simplified language that’s a mixture of two or more languages. It has words from both languages.
M: Oh, yeah. Now I remember. We studied pidgins in anthropology.
W: My professor said there are lots of different pidgins based on English that developed in different parts of the world. It was because people from English speaking countries had to communicate with the local people. Pidgins have a simple grammar and vocabulary, so they’re easy to learn.
M: That’s cool. Your class sounds interesting.
W: Yeah, we’re learning some pretty amazing stuff.