The phonology of a particular language could be hard to handle for a non-native learner, say, the word boundary and consonant clusters. One way to do is to reanalyze the syllables, e.g. to reanalyze "Stack Exchange" into "sta-keks-change" in mind and then pronounce it. Another problem is that the syllable final "-al" sounds exactly the same as "o" for one, which cause him to pronounce "all orders" as "o orders". The best way to correct his pronunciation is to tell him that there is a "liaison-like" thing, so he needs to break the syllables down and reconstruct them into "o lorders".
But I am worrying about if this may cause path dependence and finally trouble, as well as if you handle the German number system by counting the single digit first and then think about the ten digit, rather than handle the two digit number as a whole unit, which would cause you unable to use the number system skillfully in years.