it's been years that I went to frankfurt, but...
- the youth hostel frankfurt is listed in tourist guides for handicapped people, so this should be reality (in theory, every hostel and hotel should be wheelchair friendly as there are laws, but that's not the truth). Here's the link: http://www.jugendherberge-frankfurt.de/ ... ?id=55&L=1
- I think (almost) every taxi service has some special cars for wheelchairs.
- many many people speak english.