Я каждый вечер поливаю это растение тёплой водой.

Every evening I water this plant with warm water.

Breakdown of Я каждый вечер поливаю это растение тёплой водой.

• я: I
• это: this
• вода: the water
• каждый: every
• вечер: the evening
• тёплый: warm
• растение: the plant
• поливать: to water

Questions & Answers about Я каждый вечер поливаю это растение тёплой водой.

Why is it каждый вечер, and not каждый вечером or каждым вечером?

The neutral, most common way to say “every evening” is каждый вечер:

• каждый is in the accusative masculine singular, agreeing with вечер (also accusative singular, same form as nominative for inanimate nouns).
• Time expressions like каждый день, каждое утро, каждый вечер, каждую ночь are normally in the accusative.

You can hear каждым вечером, also meaning “every evening,” but it’s less common and can sound a bit more emphatic or literary, like “on each and every evening.”
каждый вечером is simply ungrammatical: the adjective and noun must be in the same case, and вечером is instrumental, while каждый here is accusative.

Why is вечер in the accusative case at all? There is no preposition.

Russian often uses the bare accusative of time to say “how often / when” something happens:

• каждый день – every day
• каждый год – every year
• этот вечер can also be used adverbially in some contexts (“this evening”).

So каждый вечер is an adverbial phrase of time in the accusative, even though there is no preposition. This is a standard pattern in Russian.

Why is it поливаю, not a form of полить? What is the aspect difference?

Поливать (imperfective) vs полить (perfective):

• поливать focuses on a process, repeated or habitual action.
  
  • Я каждый вечер поливаю это растение. – I water this plant every evening (habit).
• полить focuses on a single, complete action.
  
  • Я полью это растение вечером. – I’ll water this plant in the evening (one occasion).

Because the sentence describes a regular habit (“every evening”), Russian uses the imperfective: поливаю.

How is поливать conjugated, and where is the stress in поливаю?

Поливать is a first-conjugation imperfective verb. Present tense:

• я поливАю
• ты поливАешь
• он/она/оно поливАет
• мы поливАем
• вы поливАете
• они поливАют

The stress is on -ва-: поливАю, not пОливаю.

Why is it это растение, not этот растение?

Because растение is a neuter noun:

• Masculine: этот стол – this table
• Feminine: эта книга – this book
• Neuter: это растение – this plant

So the demonstrative must agree in gender: это + растение.

Is растение the subject here? Why does it look the same as in the dictionary?

No, the subject is я (“I”).
Растение is the direct object of поливаю:

• Subject: я
• Verb: поливаю
• Direct object: это растение

Растение is neuter inanimate, and for neuter inanimate nouns, the accusative singular = nominative singular, so it looks just like the dictionary form: растение in both cases.

Why is it тёплой водой and not тёплая вода?

The verb поливать takes two objects:

• что? (what?) – accusative: это растение
• чем? (with what?) – instrumental: тёплой водой

So водой is the instrumental case (“with water”), and тёплой is the matching feminine singular instrumental form of тёплый.
Тёплая вода is nominative (“warm water”) and would be used if water were the subject: e.g. Тёплая вода полезна. – Warm water is beneficial.

Why is there no preposition like “with” – why not с тёплой водой?

In Russian, the instrument or means of an action is usually expressed by bare instrumental case, without a preposition:

• писать ручкой – to write with a pen
• резать ножом – to cut with a knife
• поливать тёплой водой – to water with warm water

The preposition с (“with”) normally expresses accompaniment or other meanings (“together with someone”, “from / off”), not the tool/means. So поливать с тёплой водой is incorrect here.

Why does тёплой have this ending? What form of the adjective is it?

Тёплый is a regular hard-stem adjective. Its feminine singular forms include:

• Nominative: тёплая (тёплая вода)
• Genitive / Dative / Instrumental / Prepositional: тёплой

Here we need instrumental feminine singular to agree with водой, so we use тёплой водой.
The adjective must match the noun in gender, number, and case.

Can the word order change? For example, is Каждый вечер я поливаю это растение тёплой водой also correct?

Yes, Russian word order is fairly flexible. All of these are grammatical:

• Я каждый вечер поливаю это растение тёплой водой.
• Каждый вечер я поливаю это растение тёплой водой.
• Я поливаю это растение тёплой водой каждый вечер.

The basic meaning is the same. Changes in order mostly affect emphasis or rhythm, not grammatical correctness. The original order is neutral and very natural.

Can I omit я and just say Каждый вечер поливаю это растение тёплой водой?

Yes, you can. The verb ending -ю in поливаю already tells us the subject is “I”, so я is not strictly required.

• Каждый вечер поливаю это растение тёплой водой.

This is grammatical and can sound a bit more conversational or stylistic. Including я just makes the subject explicit and slightly more emphasized.

How would I say “I will water this plant this evening with warm water” in Russian, and what changes?

For a single future action, you switch to the perfective verb полить:

• Я сегодня вечером полью это растение тёплой водой.

Changes from the original:

• каждый вечер (“every evening”) → сегодня вечером (“this evening”)
• поливаю (imperfective present, habitual) → полью (perfective future, one-time action)

The rest (это растение тёплой водой) stays the same.