German Passive Alternatives (Passiversatz): sich lassen, sein + zu, -bar/-lich
Three elegant ways to express passive meaning without werden: sich lassen + infinitive, sein + zu + infinitive, and -bar/-lich adjectives.
German has three common passive alternatives (Passiversatz) that replace a clumsy werden-passive, especially when a modal meaning ("can/must be done") is involved. 1. sich lassen + Infinitiv = kann …t werden (can be done). Take a bare infinitive — no zu: Das Problem lässt sich lösen. = "The problem can be solved." 2. sein + zu + Infinitiv = muss/kann …t werden (must/can be done). The zu-infinitive carries necessity or possibility: Die Aufgabe ist zu lösen. Context decides between "must" and "can". 3. Adjectives in -bar / -lich = "…-able": lösbar (solvable), verständlich (understandable), machbar (doable). These turn the verb into a one-word adjective. All three are more elegant than repeating werden and are very common in written and formal B2 German.
Examples
Das Problem lässt sich lösen.
The problem can be solved.
Die Aufgabe ist leicht zu lösen.
The task is easy to solve / can be solved easily.
Das ist machbar.
That is doable.
Common mistakes
sich lassen takes a bare infinitive (no zu).