Na terça-feira, minha prima vai ao teatro comigo.

On Tuesday, my cousin is going to the theater with me.

Breakdown of Na terça-feira, minha prima vai ao teatro comigo.

• ao: to the
• minha: my
• ir: to go
• na: on the

Questions & Answers about Na terça-feira, minha prima vai ao teatro comigo.

Why is it na terça-feira instead of just terça-feira?

Na is the contraction of em + a.

• em can mean on / in / at, depending on context.
• terça-feira is feminine, so it can take the article a.
• So em + a terça-feira becomes na terça-feira.

In natural English, this is usually just on Tuesday.

Also, in Brazilian Portuguese, you may sometimes hear just terça-feira with no preposition, especially in informal speech:

• Terça-feira, minha prima vai ao teatro comigo.

Both are possible, but na terça-feira is very clear and standard.

Why does terça-feira have a hyphen?

The names for Monday through Friday in Portuguese are written with -feira and a hyphen:

• segunda-feira
• terça-feira
• quarta-feira
• quinta-feira
• sexta-feira

This is simply the standard spelling. You should learn them as complete words.
Notice that sábado and domingo do not use this pattern.

Why is terça-feira lowercase? In English, Tuesday is capitalized.