Portuguese Phrase
O que é o efeito estufa?
Meaning
A direct question asking for the definition of the greenhouse effect – the atmospheric process where gases such as CO₂ trap solar heat, raising Earth’s surface temperature.
When to use
Use this sentence when you want to introduce a discussion about climate change, in a science class, or when someone asks for a simple explanation of the phenomenon.
✦Grammar Breakdown
Oqueéoefeitoestufa?
O que
Interrogative pronoun phrase meaning “what”. It introduces a definition question.
é (ser)
Third‑person singular of the verb *ser*, used for permanent characteristics or definitions.
o (definite article)
Masculine singular article that agrees with the noun *efeito*.
efeito
Masculine noun meaning “effect”.
estufa
Masculine noun meaning “greenhouse”; together with *efeito* it forms the compound term *efeito estufa*.
Question mark
In Portuguese, the opening question mark (¿) is not used; only the closing “?” is required.
🗨In Conversation
O que é o efeito estufa?
What is the greenhouse effect?
É o processo pelo qual gases na atmosfera retêm o calor do sol, aquecendo a Terra.
It’s the process by which gases in the atmosphere retain the sun’s heat, warming the Earth.
✕Common Mistakes
O que ser o efeito estufa?
Use the conjugated form *é* instead of the infinitive *ser* when asking a definition.
O que é efeito estufa?
The article *o* must agree with the noun; never omit it in this construction.
↔Alternatives
O que significa efeito estufa?
What does ‘greenhouse effect’ mean?
Como funciona o efeito estufa?
How does the greenhouse effect work?
Qual é a definição do efeito estufa?
What is the definition of the greenhouse effect?
Cultural Tip
In Brazil, climate‑change topics are frequently discussed in both formal (news, academic) and informal (social media) settings. When speaking with teachers or professionals, keep a neutral tone; with friends you can shorten it to “efeito estufa”. The term is the same across Portuguese‑speaking countries, but in Portugal you may also hear “efeito estufa” pronounced with a slightly different vowel quality.