Questions & Answers about Diese Aufgabe ist schwerer als die letzte.
In German, one-syllable and many two-syllable adjectives usually form the comparative by adding -er to the adjective, not by using mehr.
- schwer → schwerer (heavy → heavier / difficult → more difficult)
- schnell → schneller
- klein → kleiner
You normally use mehr + adjective only with some longer adjectives where adding -er sounds awkward or is not standard, for example:
- interessant → interessanter or mehr interessant (the first is preferred)
- kompliziert → komplizierter (not mehr kompliziert in standard German)
For schwer, the normal and correct comparative is schwerer, not mehr schwer.