Almost everyone you meet in Amsterdam will speak English. That said, English in Amsterdam is often a language all its own (Dutchlish? Engutch? Nerderlanglish?), with its own quirks and colloquialisms. My favorite is a phrase I've seen on telephone calling cards and in the public transport station: when you want to "add value" to something, or "put money on" it, you give it a "top up," as in "would you like to top up your ov-chipkaart?"
This sounds to me either like I'm taking it on a hot-air balloon ride or I'm giving it to someone from MTV to "pimp." Yes, please top up my card! This phrasing is also used in the UK, but it's news to an American girl.