How to pronounce Calvin and Kelvin
Here is another example (for the first, see here) of what can go wrong when non-native speakers put too much effort into their American accent (in this case a successful German scientist who has been living and working in the US for many years).
The name Kelvin, used for the unit of temperature and referring to Lord Kelvin, is pronounced as [ˈkelvɪn], listen here. It is not to be pronounced as [ˈkælvɪn], that is, with the letter ‘e’ pronounced like an ‘a’ because that makes it sound like Calvin, first name of a rather well-known fashion designer. You can listen to the incorrect pronunciation of Kelvin here: