Por la noche vemos una serie famosa; ya vamos por la tercera temporada.

All three exist and can often be translated as “at night”, but they have slightly different tendencies:

• por la noche

  • Very common and neutral in all varieties of Spanish.
  • Used a lot for when something happens (often as a routine):
    
    • Por la noche vemos una serie. – At night we watch a series.

• en la noche

  • Especially common in much of Latin America.
  • Often used for a specific night or time frame:
    
    • Lo hago en la noche. – I’ll do it at night (this evening/tonight).
  • In many contexts you could swap por la noche and en la noche without changing the meaning much.

• de noche

  • Focuses more on the condition “when it’s dark / at nighttime” in contrast to the day:
    
    • Conduzco mejor de noche. – I drive better at night.

In this sentence, por la noche sounds very natural for a regular habit. In Latin America, en la noche would also be understood and often accepted, but por la noche is perfectly standard and slightly more “textbook.”

Yes, you can, and both are correct, but they feel slightly different:

• Por la noche

  • General reference to the nighttime as a period.
  • Can be used for a habit or for a specific night, depending on context.

• Por las noches

  • Stresses repetition: at nights / on nights / at night in general, often every night or most nights.
  • Sounds clearly habitual:
    
    • Por las noches vemos una serie. – At night(s), we watch a series (it’s our routine).

In practice, with a sentence about a regular activity, por la noche and por las noches are both fine; por las noches just emphasizes the idea of many nights more strongly.

In English, see and watch are clearly different. In Spanish, ver and mirar overlap a lot, and usage depends on context and region.

For TV, movies, series, etc.:

• The most natural verb (in most of the Spanish-speaking world) is ver:

  • ver una película – to watch a movie
  • ver una serie – to watch a series
  • ver la tele – to watch TV

• mirar is also used in some regions, especially in parts of Latin America:

  • mirar la tele is common in some countries.

But in a neutral, widely understood sentence, vemos una serie famosa sounds more standard than miramos una serie famosa. That’s why you see vemos here.

Spanish uses the simple present much more often than English to talk about:

• Habits / routines

  • Por la noche vemos una serie. – At night we watch a series.
  • English uses we watch or we usually watch, Spanish uses vemos.

• Scheduled or repeated actions

The present progressive (estamos viendo) is used in Spanish mainly for actions that are happening right now:

• Ahora mismo estamos viendo una serie. – Right now we’re watching a series.

In your sentence, it describes a regular habit, not what you are doing at this exact moment. So the simple present vemos is the natural choice.

ya literally means “already”, but it often carries a nuance of:

• progress
• reaching a point that might be surprising or noteworthy
• “by now”

So:

• Vamos por la tercera temporada.

  • We’re on the third season. (Neutral statement.)

• Ya vamos por la tercera temporada.

  • We’re already on the third season (by now)!
  • Suggests: Time has passed quickly, or we’ve advanced quite a bit, or it happened faster than expected.

You can omit ya and still be correct; you just lose that “already / wow, look how far we are” feeling.

Literally, vamos por looks like “we go by”, but idiomatically it means something like:

• We’re at / we’re on / we’ve reached a certain stage or point in a series, process, or amount.

In this context:

• Ya vamos por la tercera temporada.
  ≈ We’re already on season three.
  (as in: We’ve started watching season 3 / we’ve reached that point.)

Other examples with ir por in the same sense:

• Ya vamos por la mitad del libro. – We’re already halfway through the book.
• Vamos por el capítulo 10. – We’re on chapter 10.
• Van por el segundo hijo. – They’re on their second child (they already have one, and another is on the way / born).

So ir por here expresses progress / how far along you are.

Yes, both are used in everyday speech, especially in Latin America:

• Ya vamos en la tercera temporada.
• Ya estamos en la tercera temporada.

All three are understandable and can mean “We’re already on the third season.”

Nuances (which can vary by region):

• ya estamos en… – slightly more static: “We are at that point.”
• ya vamos en… / ya vamos por… – more dynamic: “We’ve gotten to that point / we’ve advanced to that point.”

In practice, for TV seasons:

• Ya estamos en la tercera temporada.
• Ya vamos por la tercera temporada.

are both very natural in Latin American Spanish, and you will hear both.

There are two issues: gender and form of “third”.

1. Gender of “temporada”

   • temporada is a feminine noun: la temporada.
   • So the adjective must also be feminine: tercera.

2. tercer vs tercero / tercera

   • tercer is a shortened form used only before masculine singular nouns:
     • el tercer día – the third day
     • el tercer capítulo – the third episode
   • For feminine nouns you use tercera:
     • la tercera temporada – the third season
     • la tercera vez – the third time

So el tercer temporada is wrong because:

• It uses el instead of la (wrong gender).
• It uses tercer (masculine) with a feminine noun.

Correct: la tercera temporada.

Both can translate as “season”, but they are used in different contexts:

• temporada

  • TV / series / sports / tourist seasons / harvest seasons:
    
    • la primera temporada de la serie – the first season of the series
    • la temporada de fútbol – the soccer season
    • temporada alta – high season (tourism)
  • Also used for periods when something is in season:
    
    • temporada de lluvias – rainy season

• estación

  • Mainly for the four seasons of the year:
    
    • la primavera, el verano, el otoño, el invierno are estaciones.
    • la estación de verano – the summer season.

For a TV show, season is always temporada, not estación. That’s why the sentence says tercera temporada.

Both are grammatically correct, but they have different nuances because Spanish adjectives can go before or after the noun:

• una serie famosa (adjective after the noun)

  • This is the more neutral / standard order.
  • It just states a fact: the series happens to be famous.

• una famosa serie (adjective before the noun)

  • Sounds more emphatic or stylistic, sometimes a bit more literary or journalistic.
  • Could sound like: “a famous series (that you probably know about)”.
  • It can put a bit more focus on famous.

In normal conversation, una serie famosa is the more typical, straightforward phrasing, so that’s what you see in the sentence.

In Spanish, every noun has a grammatical gender: masculine or feminine. The noun serie is feminine:

• la serie – the series
• una serie famosa – a famous series

Unfortunately, there isn’t a perfect rule for all nouns ending in -e; you have to learn the gender with the word:

• el coche – the car (masculine)
• la noche – the night (feminine)
• la serie – the series (feminine)

Many abstract nouns and some TV/cultural terms ending in -ie / -e are feminine (e.g. la serie, la noche, la calle), but the safest approach is to learn new nouns with el or la from the start. Here, una agrees with the feminine serie.

In Spanish, as in English, a semicolon ; can link two closely related sentences:

• Por la noche vemos una serie famosa; ya vamos por la tercera temporada.

You could also write:

• Por la noche vemos una serie famosa. Ya vamos por la tercera temporada.
• Por la noche vemos una serie famosa y ya vamos por la tercera temporada.

All three are grammatically correct. The semicolon:

• shows a stronger connection than a period,
• but keeps the two ideas slightly more separate than using y.

It’s mostly a stylistic choice, not a grammatical necessity.