Летом мы часто ездим на юг к морю, а зимой иногда едем на север в горный город.

Russian has pairs of verbs of motion:

• ехать / ездить – to go by vehicle
  
  • ехать – one direction, one trip (right now or as a single event)
  • ездить – back and forth, or in general/habitually

In the sentence:

• Летом мы часто ездим на юг…
  → ездим = “we (habitually) go / travel (by transport)” every summer; it’s a repeated pattern.

• …а зимой иногда едем на север…
  → едем here suggests each winter you sometimes set off on a particular trip to the north.
  It sounds like individual trips that may or may not happen in a given year.

You could also say …а зимой иногда ездим на север… – then both parts would sound equally general and habitual. With едем, the second part feels a bit more “concrete, individual trip” each time it happens.

Russian distinguishes going on foot vs by transport:

• идти / ходить – to go on foot
• ехать / ездить – to go by vehicle (car, train, bus, plane, etc.)

Travelling south to the sea and north to a mountain town is naturally understood as going by some transport, not walking, so ехать / ездить are used:

• ездим на юг к морю – we go/travel (by transport) south to the sea
• едем на север – we’re going (by transport) north

Words for seasons and parts of the day often appear in the instrumental case without a preposition to express “in/at that time”:

• летом – in (the) summer
• зимой – in (the) winter
• similarly: весной (in spring), осенью (in autumn), утром (in the morning), днём, вечером, ночью

Saying в летом or в зимой is incorrect. You just say:

• Летом мы часто ездим… – In summer we often go…
• Зимой мы иногда едем… – In winter we sometimes go…

Russian prepositions with places:

1. на + accusative for direction:

   • to open spaces, surfaces, events, or broad regions
   • also for points of the compass

   So:

   • на юг – to the south (direction)
   • на север – to the north (direction)

2. в + accusative for direction:

   • to closed spaces, buildings, cities/towns, and many specific places

   So:

   • в горный город – to a mountain town/city (literally “into a mountain town”)

So you go:

• на юг, на север (to the south, to the north – directions/regions)
• в город / в горный город (to a specific town/city)

• на юг – direction (accusative):

  • Куда? (Where to?) → на юг – to the south

• на юге – location (prepositional):

  • Где? (Where?) → на юге – in the south

Examples:

• Летом мы часто ездим на юг. – In summer we often go to the south.
• Летом мы часто отдыхаем на юге. – In summer we often relax in the south.

Same pattern for the north:

• на север (to the north) vs на севере (in the north).

All three exist, but they mean different things:

• к морю – towards / to the sea (shore)

  • focus on movement toward the sea as a place, often meaning “to the seaside”
  • морю is dative singular after к

• в море – into the sea / in the sea (in the water)

  • e.g. корабль ушёл в море – the ship went into the sea

• на море – fixed phrase: “at the seaside / to the seaside”

  • Мы летом ездим на море. – We go to the seaside in summer.

In the sentence:

• на юг к морю literally: “to the south, to the sea”,
  meaning “to the south, to the seaside (coast)”.
  It stresses the idea of heading toward the sea/coast, not into the water itself.

Because of the preposition к:

• к
  • dative = “towards / to (a person or object/place)”

Declension of море (sea):

• nominative: море
• dative: морю

So:

• к морю – to/towards the sea (dative after к)
• Compare: к другу (to a friend), к дому (towards the house)

The difference is direction vs location:

• в + accusative → direction, куда? (where to?)

  • в горный город – to a mountain town

• в + prepositional → location, где? (where?)

  • в горном городе – in a mountain town

In the sentence, we are describing movement:

• едем на север в горный город – (we) go north to a mountain town.

If you wanted to talk about being there:

• Мы живём в горном городе. – We live in a mountain town.

горный is an adjective from гора (mountain). It generally means:

• mountain / mountainous

So горный город is:

• a town/city in the mountains,
• or a mountain resort town, depending on context.

It doesn’t by itself say whether it’s big or small; город just means town/city, and горный specifies that it is mountainous / in the mountains.

Both а and и can be translated as “and”, but they differ:

• и – simple “and”, adds information without contrast.
• а – “and” with a contrast or comparison, often like “whereas” or “but”.

Here:

• Летом мы часто ездим на юг к морю, а зимой иногда едем на север…

The speaker is contrasting what they do in summer vs winter:

• In summer → often go south to the sea
• In winter → sometimes go north to a mountain town

So а is the natural choice: it highlights the difference between the two seasons.

Yes, Russian word order is flexible. All of these are possible and natural, with small differences in emphasis:

For the first clause:

• Летом мы часто ездим на юг к морю. (neutral)
• Летом мы ездим на юг к морю часто. (emphasis at the end)
• Мы летом часто ездим на юг к морю. (slight emphasis on “in summer”)

For the second clause:

• …а зимой иногда едем на север в горный город. (neutral)
• …а зимой едем на север в горный город иногда. (emphasis that it’s only sometimes)
• …мы зимой иногда едем на север… (emphasis a bit more on “in winter”)

Position changes can shift focus, but часто and иногда almost always stay close to the verb they modify.

This is actually the same use: Russian present tense can express habitual / repeated actions, just like English present simple:

• Летом мы часто ездим…
  → Literally: “In summer we often go (are going)…”
  → Meaning: We regularly, habitually go in the summer.

• …а зимой иногда едем…
  → “and in winter we sometimes go…”

If you said будем ездить or будем ехать, that would emphasize future repeated actions, not the general habit you already have. Here the speaker describes a current, regular pattern in their life, so simple present in Russian works naturally.

No. In Russian, names of seasons and months are not capitalized in normal usage.

In the sentence, Летом is capitalized only because it is the first word of the sentence. If it were in the middle of a sentence, you would write:

• Мы летом часто ездим на юг к морю.

So:

• English: Summer / Winter (often capitalized as nouns)
• Russian: лето, зима, летом, зимой – normally lowercase, except at the start of a sentence.