There are some who can speak English, and you can have your hosts (like say, the people at the hotel you are staying at in Can Tho) put you in contact with one such taxi driver.
There are bicycle rental places in Can Tho, though actually getting a suitable bike may be tricky – especially if you are person of a bigger/heavier physical build. There are also places where motorbikes are rented out, and you can hire one such machine to get around Can Tho.
Yet another option for getting around Can Tho is using a ferry. To catch a ferry, you need to go to one of the ferry stations located at the Ninh Kieu quay. Another approach you can use to travel by water in Can Tho is that of renting a private boat. One of the places where you can do that is at Ninh Kieu Pier.
Can Tho is a relatively big city, and the idea of getting around by foot may be outlandish. Much, however, depends on exactly which part of the city you want to explore, as many tourists tend to focus on the area around the Quay, which definitely can be explored on foot.