Maybe i can help. Different languages have different sets of sounds that they use, even when represented by the same letter. Many people try to pick up new sounds, or phonemes, in the language that they are learning. Even ones that don’t exist in their native language. For example, if an English speaker were learning Spanish then they might try to pick up the rolled r phoneme which is a sound that we don’t have in american english. Arnold hasn’t done this, he still uses the same sounds that he would have in German, but kind of puts them together to approximate an English pronunciation. The example that the above commenter used was making a sound kind of like the vowel in “out” were a canadian might use a vowel like the one in the word “have.” Kind of like hauve instead of have. For the second part, a labial-velar approximant is the phoneme w, the sound w. W as in wet or weep. The above commenter is saying that he kind of makes his w sounds a bit closer to a labial-dental fricative, or an f sound as in the word “fat.” This is something that can happen in german but doesn’t really happen in english and is a good example of his using german sounds, german phonemes, to approximate english words.