With so many Americans and Europeans renting and buying Isla Mujeres real estate these days, Spanish is not essential on Isla, most Island people you come into contact with will speak and understand enough English for you to make yourself understood. However if you do speak some Spanish the locals are very patient and will help you to get your message across in Spanish, even if the speak perfect English.
As far as getting around Isla Mujeres is concerned golf carts are often favoured by tourists, however they are not cheap, if you are going to hire one for some period of time. And of of course the best Isla Mujeres real estate is not that close to the town centre and whilst Punta Sur is only 10 - 15 minutes away from the centre in a taxi it can become a bit of a drag going back and forth in a golf cart.
Taxis are not expensive and are a very practical way of getting around, however there is a tendency with some taxi drivers to somewhat overcharge foreigners . So it's worth negotiating the fare at the outset of your journey. It's easy to understand the thought process; they see that you are renting or buying Isla Mujeres real estate and probably think - not without some justification - that you can afford to pay a bit more and it will still be cheap by US standards.
If you are staying in one of our villas at Las Faroles at the southern part of island where a lot of the luxury Isla Mujeres real estate is located, there are a number of taxi drivers you can call upon to take you into town and will always charge you a fair price they are as follows:
Capo 998 122 6166
Angel 998 130 2472
Lisbet 998 153 0658
Abel 998 259 0091