Many people complained about my not using capitals at the beginning of the sentence (it has been "corrected" in the mean-time).
I think, the rule of using a capital at the beginning of a sentence is trivial and can be dominated by any learner right away. But knowing in German which words have to be spelled with capital (nouns, as first approximation) and which not is not at all trivial, and has been modified several times by the orthographic reforms and re-re-re-...-re-reforms during the past years.
In the expample above, "Glaube" is a verb form and normally spelled "glaube" with minuscule. There is also the noun "Glaube" spelled with capital. For the learner, the grammatical structure might not be that clear, therefore, I think, it would help him/her to discard the trivial rule of spelling with a capital at the beginning of a sentence and thus show the normal spelling of the word.

You should also consider that hte learner could find a sentence like this one elsewhere, and then he has to be able himself to distinguish if "Glaube" means the noun or the verb...

@Muiriel: Sure a learner has to be able to distinguish the different cases elsewhere -- once he has learnt it, it won't be a problem. But why not help him while he is learning?

@arcticmonkey: You're literally right with "far-fetched": It originates from the experience of my BRAZILIAN wife learning German! :-)) Mit Verlaub: Your's a typical so-called killer argument...

The comments so far came from native Germans, who normally should not have any problem in recognizing the grammatical form of a German word in a German sentence.
Any comments from non-native Germans who are in the beginning of learning German or can remember how it was and what they struggled with?

Duplicates of this sentence have been deleted:
x #5594873