Heuristic whether a verb which could be either separable or unseparable is separable or unseparable

Question

The Problem

The following verb prefixes are able to form both separable and unseparable verbs.

• durch-,
• über-,
• unter-,
• um-,
• wider-,
• wieder-

There are even verbs which are homograph, where one version is separable and one is not, and the meaning is different. In this case, the word stress is different: for separable verbs, it is on the prefix, for unseparable verbs it is on the verb stem.

The question “Wir wären bereit die Küche zu übernehmen / überzunehmen.” made me wonder whether there is a pattern for language learners to identify or to memorize which of the verbs are separable and which not, judging only by the meaning of the verb.

The question Únterlegen vs. unterlégen has an example where the distinction seems to depend on transitive or intransitive use of the verb. But I think, this is rather an edge case.

Possible Solution I: Transient vs. Permanent?

One answer on the question Why are some verbs separable, and others inseparable, even though the prefixes are the same says:

The non-separable ("permanent") prefixes refer to permanent conditions, and the separable prefixes to temporary conditions.

However, I do not give much credit to this idea, because I find too many counter-examples, where the hypothesis either seems to be wrong, or where such a distinction between permanent and transient meaning does not even seem to make sense, for instance: durchlaufen, durchsuchen, umschreiben.

Possible Solution II: More Literal Meaning vs. More Figurative Meaning (of the Prefix)?

From a rough guess, I'd have said that the prefix in the separable versions seems to have a more literal meaning than in the non-separable version. For instance:

• úmgehen (separable: "to go around"), vs. umgéhen (unseparable: "to circumvent")
• úmschreiben (separable: "to re-write"), vs. umschréiben (unseparable: "to describe")
• in etw. ǘbergehen (separable: "to turn into sth.", literally: "to go over into sth.") vs. übergéhen (unseparable: "to run over")

But this is just my impression and not backed by any research. I wouldn't be surprised if there are a lot of counterexamples. The author of this site also seems to have a similar idea:

Wie kannst Du unterscheiden, ob ein und dasselbe Verb trennbar oder nicht trennbar ist? Stelle Dir folgende Frage: Hat das Verb in diesem Kontext nur eine abstrakte, übertragene Bedeutung? Dann ist der Präfix meist nicht trennbar.

How can you decide, whether a verb is separable or not? Ask yourself: Does the verb have an abstract, figurative meaning, in that context? In this case it is often not separable.

Questions

So, basically, I have two questions:

1. Is my above mentioned hypothesis ("Possible Solution II") correct, or at least a good rule of thumb?

2. If not, is there another rule, or at least a rule of thumb how language-learners can guess which variants are separable and which ones are not?

Answer 1

I don't think it has anything to do with the meaning of the verb. Here is a simple explanation (from here):

Ob ein Verb trennbar ist, erkennst du oft daran, welches Präfix es hat.

Verben mit Präfixen wie z. B. ab-, an-, auf-, aus-, ein-, mit-, nach-, weg-, zu- sind immer trennbar. Im Gegensatz dazu sind Verben mit Präfixen wie z. B. be-, ent-, er-, ver-, zer- nicht trennbar. Verben mit Präfixen wie durch-, über-, um-, unter- können trennbar oder untrennbar sein.

Du kannst trennbare Verben auch an ihrer Aussprache erkennen. Bei trennbaren Verben ist das Präfix immer betont.

That is, the "heuristic" to recognize separable verbs is the pronunciation. Separable prefixes are stressed while inseparable prefixes are unstressed.

It seems that many (or all?) separable prefixes where originally pronouns, while the inseparable prefixes don't (all?) exist as separate words. But this heuristic doesn't help with the prefixes than can sometimes be separated, sometimes not.