Ist "Es weiß ich" gutes Deutsch?

Question

I know Das weiß ich works

And also Ich weiß es

So what is the reason you can't start the sentence with the pronoun "es"?

Answer 1

Was ist hier kaputt? — Es weiß ich. Ich weiß es.

but e.g.

Passiert sowas öfters? — Es kommt vor.

So it's not about a dummy object not leading the sentence, as suggested in the comments. It's rather a dummy object never thrusts the real subject aside.

Answer 2

To make the answer clear: in all but fringe cases „No!“

The question is not as hard as it may at first appear. The neutral way would be to start with the subject, just like in English:

Ich weiß es/I know it

If you diverge from this pattern, it is because you want to stress an element other than the subject. Let’s say the object. Consider this traditional advice against lightning bolts!

Eichen sollst du weichen, Buchen sollst du suchen/Oaks you shall avoid, beeches you shall seek.

Both in German and English, the object is brought to the forth, so as to underscore it and thereby the distinction! While grammar does not forbid doing that in your example sentence (see addendum), it sounds more than a little weird and there are better alternatives! Why? Because es doesn’t transport a lot of meaning. If you want to stress it, you might additionally replace it by a demonstrative pronoun. Hence, the more idiomatic choice:

Das weiß ich!

Much like we prefer „that I know!“ over „it I know!“

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Addendum on why dummy objects mentioned in comments do not apply here

Dummy pronouns are very hairy animals, of which even the classic cases “es regnet, es schneit...” have been disputed in their nature as dummies. If I am forced to include them in my reasoning, I will go by the definition:

a pronoun used to fulfill the syntactical requirements without providing explicit meaning.

In the case in question we have no indication that es carries no meaning. Consider the exchange:

Weißt du wo der Hammer liegt?

Ich weiß es!

Es has a meaning and points to „wo der Hammer liegt“, that’s why we cannot omit it in this context. But es doesn’t only fulfill syntactic requirements, because in other contexts Germans indeed accept omission:

Ich weiß!

This places the es here in a different category than the es in „es regnet, es dämmert, es tagt“(dummy subjects), which are all rendered ungrammatical by removing es, or in “er läßt es sich gut gehen”(dummy object) Conclusion 1: This type of es is not a dummy!

Furthermore, if I were to replace wissen by kennen I can immediately invent valid sentences to refute the claims in the comments.

Warum zog er das Kind hinzu?

Es kannte er, den Vater nicht.

Yes, it is a very rare case and sounds poetic, but it is absolutely correct. It is as correct as Schiller’s phrase

ihn schlugen die Häscher in Bande

It is only due to the better alternative of the demonstrative pronoun that this type of construction with es has come to sound very awkward. Thereby we see, that unless we want specific rules for different very similar verbs, Conclusion 2: we cannot propound any arguments against this type of es in the front. The grammar in its full, native complexity does not forbid this. It is just overeagerness to describe everything by the rules one knows, which lead to contrary claims!

On comment by OP: Why this rule with the dummy object

This rule about not pulling real dummy objects to the front （see here, page 2) probably originated precisely from the fact that non dummy es as discussed above is correct. Consider the idiom:

Er läßt es krachen

We cannot pull es to the front without stressing it. If we stress it, it cannot be a dummy, which by definition carries no meaning. However the following highly constructed verse is grammatically correct: „er hat ein Tischlein, das er haßt, es läßt er krachen wann’s ihm paßt, die anderen Tische pflegt er“.

Answer 3

I'm not entirely happy with some of the other responses/comments here. Generally speaking, it would indeed be quite natural if the example sentence worked. The immediate reason why this is not the case is that es behaves somewhat out of the norm.

See Hans-Werner Eroms, Syntax der deutschen Sprache, 2000, p. 358 (boldface added):

Alle Ergänzungen sind vorfeldfähig, und zwar in so gut wie allen morphologischen Formen. Es gibt nur ganz wenige Restriktionen. So lässt sich das Pronomen es nicht in das Vorfeld plazieren.

["Vorfeldfähig" refers to the ability of a sentence element to be placed in the position ahead of the finite verb (= Vorfeld), i.e., in your example, ahead of weiß. Eroms points out the case of es, which, exceptionally, lacks this ability.]

Peter Gallmann in Duden, Die Grammatik, 8th ed. 2009, recital 1382, points out, slightly more broadly, that the following elements either cannot or can only under limited circumstances, appear in the Vorfeld (boldface added):

Schwach betonte Personal- und Reflexivpronomen, außer als Subjekt. Insbesondere erscheint das Pronomen es praktisch nur als Subjekt oder Platzhalter im Vorfeld. Beispiel mit es als Objekt:

*[Es] weißt [du] [ganz genau]. (Stattdessen:) [Das] weißt [du] [ganz genau]. (Oder:) [Du] weißt [es] [ganz genau].

_{Bonus track: If you are really interested in learning why this is so, I would submit that this appears to be a question more suitable for a research project than for a thread on this site. That being said, Eroms conjectures it might have something to do with a desire to avoid ambiguity:}

_{Der Grund dafür kann vielleicht darin erblickt werden, dass im Vorfeld nur das expletive es oder das pronominale es als Subjekt stehen kann. Mögliche Ambiguitäten werden auf diese Weise blockiert.}

_{Another explanation is offered by Gisela Zifonun et al., Grammatik der deutschen Sprache, vol. 2, 1997, p. 1584:}

_{Es scheint also keine rein strukturellen Gründe für die Nicht-Vorfeldfähigkeit von akkusativischem es zu geben; der Grund ist wohl am ehesten darin zu sehen, daß hier eine so schwach ausgeprägte Form in einer - wenn auch relativ gering - markierten syntaktischen Funktion, als Akkusativkomplement, auftritt. Das heißt, eine strukturell markierte Einheit braucht offensichtlich auch ein gewisses Minimum an morphologischer und phonetischer "Substanz", um an exponierter Stelle am Satzanfang stehen zu können.}