Learn Spanish (Latin America): La niña suda cuando está en la oscuridad.

We use the normal present tense because this sentence describes a habit or a recurring event. Every time she is in the dark, she sweats. When talking about general facts and routines, cuando is followed by the present indicative tense. If we were talking about a specific event happening in the future, Spanish would require a different verb form.

Why do we use está instead of es for 'is' in this sentence?

We use está (from the verb estar) because being in the dark is a temporary physical condition or a location. The verb estar is used for how you feel or where you are right now, whereas ser is used for permanent traits or identity.

Is there a rule for why oscuridad is feminine (la oscuridad)?

Yes! In Spanish, almost all nouns ending in -dad are feminine. This ending is similar to '-ity' or '-ness' in English (like 'darkness'). Other common examples are la ciudad (the city) and la universidad (the university).

What is the infinitive form of suda?

The infinitive is sudar, which is a regular verb meaning 'to sweat.' If you want to use the noun 'sweat' instead of the verb, the word is el sudor.