The pronunciation of “fen” can vary depending on the language. In English, “fen” is pronounced /fɛn/. The “f” sound is like the first sound in “father”. The “e” is pronounced like the “e” in “bed”. And the “n” is a simple nasal sound. For example, in the word “fenland”, it is pronounced this way. It's important to note that in different accents and dialects, the pronunciation might vary slightly. But this is the general way to pronounce “fen” in standard English.