Will Swahili be useful if I go to Zanzibar during holidays?
Also, can you get along by only speaking Swahili in Zanzibar? I heard they also speak English
I've been before. I grew up in Kenya, so I speak quite informal swahili. I didn't use it much, using my english more; I got around perfectly fine. It's high for tourism, so like most places speak English and French well.
Swahili will definitely be useful, especially if you plan to go outside of stonetown where less tourists go! If you only speak Swahili, you'll have no problems.
Of course Swahili will be useful anywhere in Tanzania mainland and zanzibar.. I live here and I can assure you that