What is the difference between wandeln and umwandeln ?Feel free to just provide example sentences.

Umwandeln means changing one thing into another. It's specific. You could say. Ich wandle eine Word Datei in eine PDF um. Ich change a word file into a pdf file. Wandeln is a more general verb. It simply means change. In some situations the words can be used interchangeably. Wandeln is also an old fashioned term for walking. And there are other verbs with other pre syllables that um. For example "ab"wandeln. It means changing sometimes slightly or "ver"wandeln. Changing something completely. I hope I could help you.