The mother language in Tanzania is Swahili. In addition to that there are several tribe languages, as an example the Maasai people is speaking a language called Maa. Even though many knows a little English, and especially in town most people you meet speak English, some more, others less.
In the local villages there are few people speaking English, but all Tanzanians have one thing in common, they all like to speak with guests. They love when people from other countries come to visit them, and they will try their best to communicate, in any language.