When is it justified to drop 'es' in a sentence?

Question

Take for example a sentence like

Doch sollte daran erinnert werden, dass . . .

The way I see it, and the way I would write this had I wanted to express the same thing, would be

Doch es sollte daran erinnert werden, dass . . .

I have noticed that it's fairly common to omit es, but I'm wondering if there are any rules that govern when this is permissible? I believe the grammatical term for instances such as the one I'm talking about is Platzhalter es, somewhat similar to an English construction like "It is raining" (do correct me if I'm wrong though). I do not yet have enough Sprachgefühl to make a confident judgement on when it's fair to drop the Platzhalter es (most notably in passive voice constructions), so any advice/guidance/links would be appreciated.

Answer 1

"Es" as a subject replacement (Expletivum) can generally be dropped from a sentence when it can be ensured otherwise that the verb is in the second (logical) position. German, unlike many other languages (and that's probably why many non-native speakers feel that something must be missing), doesn't really need a subject to form a proper sentence, as long as the above condition is met.

In your example, the "doch" covers the requirement that the V2 rule is met by occupying the "Vorfeld". If it's removed from the sentence, it's no longer a grammatically well-formed German sentence.

There are some minor exceptions to this rule - "regnen", "schneien" and other verbs relating to weather activities and similar "realm conditions" (e.g. "es stinkt") definitely need "es" as a subject, even if V2 placement could otherwise be met.

The fact that "es" is used only to ensure the V2 condition (rather than being the subject) can be checked in many cases by replacing it with the particle "da" or the adverb "hier" - If the sentence still works, the assumption is true - This BTW works in your example as

Da sollte daran erinnert werden, dass ...

On the other hand, there are cases where "es" is simply not allowed in sentences - this is mainly the case for sentences using an impersonate passive like in

Auf den Fluren darf [no es!] nicht gesungen oder musiziert werden

This sentence definitely wouldn't work with any subject whatsoever - This shows that German sentences are perfectly fine with having no subject at all as long as the V2 condition is met.

Answer 2

The so-called expletive es (Platzhalter) is not a subject. 1. It does not agree with the finite verb and 2. it cannot appear in subordinate clauses (in fact, it can only appear in first position).

1. Es wurden neue Regeln beschlossen.
2. seit (*es) neue Regeln beschlossen wurden

Expletive es can occur in clauses that have a subject, as is the case in the two examples above, but also in clauses that do not have a subject, as is the case in your example with the impersonal passive.

The fact that it is not a subject and restricted to first position distinguishes expletive es from other types of es that are subjects: 3. es as the subject of weather verbs and as the subject of fixed expressions; 4. correlative es, referring to a postponed subject clause; 5. anaphoric es, referring to a preceding noun.

3. seit es ständig schneit
   wenn es um die Wurst geht
4. obwohl (es) sich gezeigt hat, dass das Risiko gering ist
5. ein Kind, wenn es erwachsen ist

The correlative es is very whimsical, sometimes being obligatory, sometimes dispreferred. When it is dropped, the clause it refers to becomes the subject.

Disregarding optional correlative es, es as a subject cannot be dropped, sharply distinguishing it from expletive es.

Answer 3

In general, seen from a semantical context and only with focus on your "sollte"-example, the cases where "es" is explicitly used, are identical to the reduction cases. A quite possible subtile difference in how the sentence is perceived could maybe found with focus on the actual subject of speech. For example for a direct speech with humans involved into the context as passive or quite active subjects of speech, the german "es" might be perceived as a bit inappropriate since a priori, it's too abstract or "nonhuman"/objectified. Typically for such cases, you could think of a reduction of the german "man" instead (grammatically seen, that's wrong I know since that requires a passive to active transition further on), which is more explicit about the subject of speech.

A more concrete example to emphasize this aspect might be a personal manual that further on might contain a lot of quite repetitive and accumulated points and recommendations. To emphasize, that the manual "should speak to the reader" in a quite direct way and further on to reduce repetitive overhead, the reduction of "es" is commonly seen here:

"Hierbei sollte berücksichtigt werden, dass ..., sollte sich auch klargemacht werden, dass..., sollte aber keinesfalls angenommen werden, dass..."

Here you can also see, that the reduction version can be used for concatenation in a readable fluid way (with possible semantical augmentations) in contrast to the according version with "es".

See also this very related question (and my answer there :) ):

Explaining „es“ in „jmd. hat es mit etw. zu tun haben“