Летом я плаваю в реке.

In summer, I swim in the river.

Breakdown of Летом я плаваю в реке.

• я: I
• в: in
• река: the river
• плавать: to swim
• летом: in summer

Questions & Answers about Летом я плаваю в реке.

What is Летом? Why is there no preposition, and why does it end in -ом?

Летом is the instrumental-case form of лето used adverbially to express “when.” In Russian, seasons (and some times of day) often take the instrumental suffix and drop any preposition to mean “in/during [that season].” Compare: утром (“in the morning”), ночью (“at night”).

Why is the verb плаваю used instead of плыву?

Russian has two imperfective verbs for “to swim”:

• плыть (unidirectional) describes a single, continuous movement in one direction.
• плавать (multidirectional) describes habitual, repeated, or general swimming ability.
  Here плаваю (1 sg. present of плавать) tells us “I habitually swim” or “I can swim,” fitting the meaning “I swim regularly in the river during summer.”

Why is в реке in the prepositional case rather than accusative?

With the preposition в, you choose accusative for motion into something, but prepositional for location in something.

• в реку (acc.) = “into the river” (movement).
• в реке (prep.) = “in the river” (where the swimming happens).
  Since you’re describing where you swim, you use the prepositional: в реке.

Do you have to include я? Could you say Летом плаваю в реке?

No, you don’t have to. Russian verb endings already show the subject, so you can omit я:

• Летом плаваю в реке.
  Including я adds emphasis or clarity: “As for me, I swim in the river in summer.”

Why is the word order Летом я плаваю в реке instead of Я плаваю в реке летом?

Russian word order is flexible and used for emphasis.

• Летом я плаваю в реке foregrounds when (“In summer…”).
• Я плаваю в реке летом is also correct but more neutral, ending on the time expression.

What tense and aspect is плаваю?

плаваю is present tense and imperfective aspect (first person singular) of плавать. It expresses an ongoing or habitual action.

How would you say “This summer I will swim in the river” using perfective aspect?

To express a single or completed action in the future, use the perfective поплавать plus a future form of быть or the simple future of the perfective verb:

• Летом я поплаваю в реке. (simple future)
  This means “This summer I will swim (at least once) in the river.”