I'm not fully sure of how to go about conveying the meaning of sentences like "I should be going to bed now" or "He should be speaking decent English". I think part of my problem may stem from the fact that I'm not even sure what you would call the "be [infinitive verb] + ing" part in English.
Let's take my second example: "He should be speaking decent English"
I imagine that one could possibly translate this as "Er soll gut Englisch sprechen", without any trace of "be speaking", but I feel this is losing some information. In English, the two phrases "He should speak good English" and "He should be speaking good English" are not exactly equal.
The former is implying that he probably speaks good English, where as the latter is implying that he is expected to speak good English.
Is there a compact way of translating this into German, or is it necessary to change the sentences to be more explicit in meaning?