The Low: Drop
While it is a grammatical rule in some languages, in others like English, it is often associated with informal registers, such as diary entries , text messages, or casual spoken conversation (e.g., saying "Seen it" instead of "I have seen it"). Topic Drop Across Languages
German topic drop clauses are a subtype of declarative clauses where the initial position (usually filled by an overt constituent) ResearchGate Drop the Low
Topic drop occurs when a speaker leaves out an element that has moved to the "sentence-initial" position, typically because it was already mentioned in the previous discourse. While it is a grammatical rule in some
Topic drop in German: Empirical support for an information-theoretic account to a long-known omission phenomenon The frequency and rules for dropping topics vary
It primarily happens at the "left edge" or beginning of a clause.
The frequency and rules for dropping topics vary significantly between language types: Topic drop in German: Grammar and usage - ResearchGate
The omitted information must be predictable and easy to recover for the listener.