I've always said that the challenge with Afrikaans is the vowels. Every language has its difficulty - with German it's the verbs, with English it's the pronunciations, and with Afrikaans it's the vowels. There are just so many vowel combinations and different sounds that are hard for a native-English speaker. I struggle to make the eu, ui and uu sounds.
Today, I learned a new Afrikaans word: eeue-oue. That means "centuries-old." Notice how there are seven vowels and not a single consonant. I rest my case.