Hey Bernice, I'm a British guy that lived in Bangkok for 6 years.
Me and my wife used several different hospitals for things that were routine. Also some less routine stuff like I had an appendectomy in a hospital called Paolo, and our son was born in Samitivej (which is one of the more expensive hospitals).
The care that we received even at some of the cheaper hospitals was really good and at a very reasonable price compared to private healthcare in the UK.
Most of the hospitals are setup for medical tourism and there will be someone there that speaks English, sometimes they have a translator. But at some of the most well known hospitals like Samitivej, Bumrungrad and Bangkok Hospital most of the doctors speak good English themselves.
I can personally recommend Samitivej, they were great from start to end and all the doctors spoke really good English. Although as I said they're not the cheapest.