Spanish Phrase
Es una fiesta de cumpleaños.
Meaning
This sentence states that the event being talked about is a birthday party. It is a simple declarative sentence used to identify the nature of a gathering.
When to use
Use this phrase when you want to tell someone what kind of event is happening, for example when answering a question about plans, describing an invitation, or announcing the occasion on a social media post.
✦Grammar Breakdown
Esunafiestadecumpleaños.
Ser (es)
Use the verb ser to identify or define something. Here it tells what the event is.
Indefinite article (una)
Una is the feminine singular form of 'a/an' and must agree with the feminine noun fiesta.
Noun gender (fiesta)
Fiesta is a feminine noun, so adjectives and articles that modify it are also feminine.
Preposition de
De links two nouns to show a relationship, here 'de cumpleaños' means 'of birthday'.
Compound noun (cumpleaños)
Cumpleaños is a compound noun meaning 'birthday' and stays singular even when referring to a party.
🗨In Conversation
¿Qué vas a hacer este fin de semana?
What are you going to do this weekend?
Es una fiesta de cumpleaños.
It's a birthday party.
✕Common Mistakes
Está una fiesta de cumpleaños.
Use ser (es) for defining what something is; estar (está) is for location or temporary states.
Es un fiesta de cumpleaños.
Fiesta is feminine, so the article must be una, not un.
↔Alternatives
Es una celebración de cumpleaños.
It's a birthday celebration.
Vamos a una fiesta de cumpleaños.
We're going to a birthday party.
Hay una fiesta de cumpleaños.
There is a birthday party.
Cultural Tip
In many Spanish‑speaking countries birthday parties often include a piñata, a "torta" (cake) with candles, and the singing of "Feliz cumpleaños". The phrase is neutral and works in both formal and informal contexts, but you might add "¡Vamos a celebrar!" for a more enthusiastic tone.