When you compare two nouns or simple things in Spanish, you typically use que (e.g., más alta que la colina - "taller than the hill"). But if you want to compare an adjective or adverb to an entire action or verb clause—like "than we thought" or "than it seems"—the rules change.
Clausal Comparatives with "de lo que"
To compare a description to a conjugated verb, replace que with the neuter phrase de lo que.
The formula looks like this: más / menos + adjective / adverb + de lo que + conjugated verb
| The air here is scarcer than we thought. | El aire aquí es más escaso de lo que pensábamos. |
| Climbing this mountain was a harder challenge than it seemed. | Escalar esta montaña fue un reto más duro de lo que parecía. |
Think of the neuter pronoun lo as representing an abstract idea, translating roughly to "that which" or "what." Literally, you are saying the air is more scarce of what we thought!
Using "menos ... de lo que"
This same structure applies when using menos (less) to describe a situation that wasn't as intense as expected.
| Avalanches are less deadly than they say. | Las avalanchas son menos mortales de lo que dicen. |
| Is the challenge less complicated than it seems? | ¿El reto es menos complicado de lo que parece? |
Mixing Tenses
Notice that the verb after de lo que can be in any tense. Whether climbing the abyss is more stressful than you imagine right now, or the altitude was harder than you expected yesterday, the linking phrase de lo que never changes.
| Climbing near the abyss is more stressful than you imagine. | Escalar cerca del abismo es más estresante de lo que imaginas. |
| Enduring the altitude is harder than they expected. | Resistir la altitud es más difícil de lo que esperaban. |