Learn Hardcore Russian: Я жду письма от него.

Using the infinitive ждать here (Я ждать письма...) would be ungrammatical unless it were part of a different construction (e.g., Я буду ждать письма – I will wait for the letter).

Why is it письма here and not the dictionary form письмо?

The dictionary form письмо is nominative singular (the form you look up).

In Я жду письма от него, the noun письмо is changed to письма because it is in the genitive singular case, required by the verb ждать in this context.

Basic forms of письмо:

Nominative singular: письмо – a letter (subject)
Genitive singular: письма – of a letter / a letter (as object with certain verbs)
Nominative plural: письма – letters
Genitive plural: писем – of letters

What case is письма, and why does ждать use that case?

Письма here is genitive singular.

Many Russian verbs (including ждать, искать, добиваться, требовать, etc.) classically take their object in the genitive case, especially when talking about something that is not yet present, is indefinite, or is partly/abstractly meant.

So the pattern is:

ждать чего? – ждать письма, ждать ответа, ждать поезда

For a learner, a safe rule is:

With ждать, use the genitive (чего?) for the thing you are waiting for: ждать письма.

Could I say Я жду письмо от него instead? What’s the difference?

You can hear Я жду письмо от него in colloquial speech, and it will be understood, but:

Я жду письма от него (genitive) is the standard, neutral form.
Я жду письмо от него (accusative) sounds more colloquial and tends to imply a very specific, concrete letter that both speakers know about.

In practice:

For learners and in neutral speech, prefer genitive: ждать письма.
You will meet accusative with ждать (e.g. ждать автобус, ждать поезд), but the genitive is safer and more textbook-correct, especially with abstract or not-yet-existing things like письмо, ответ.

In English we say “wait for a letter.” Why is there no word for “for” in Я жду письма?

Russian often does not use a preposition where English uses for. Instead, the verb directly governs a case:

English: wait *for something*
Russian: ждать чего (genitive), with no preposition

So ждать письма literally looks like to wait letter (genitive), but that construction itself already expresses wait for a letter. Adding a preposition like для or за here would be incorrect.

What does от mean here, and why от него instead of some other preposition?

От is a preposition that generally means from in the sense of:

from a person or source
away from something

In письмо от него, от indicates the sender or source: a letter from him.

Compare:

письмо от него – a letter from him (he is the sender)
писать письмо ему – to write a letter to him (he is the recipient)
идти от него – to go away from him

You wouldn’t use из here, because из usually means from inside (a place), e.g. из дома – from the house, из Москвы – from Moscow. With people as senders/sources, от is the normal choice.

Why is it от него and not от он or от ему?

Because after prepositions like от, the pronoun он must go into the genitive case.

Forms of он:

Nominative: он – he (subject)
Genitive: его / него
Dative: ему
Accusative: его / него
Prepositional: о нём

With от, you need the genitive answer to от кого? – from whom?:

от кого? – от него – from him

Why него and not его?

After most prepositions, Russian uses the n-forms (него, него́, неё, них) to avoid awkward sound combinations, so:
- у него, к нему, от него, для него etc.

Can I change the word order, for example: Я жду от него письма or Письма от него я жду?

Yes, Russian word order is quite flexible, and all of these are grammatically possible, with slightly different emphasis:

Я жду письма от него. – Neutral, straightforward; focus on the whole situation.
Я жду от него письма. – Slight emphasis on от него (from him rather than from someone else).
Письма от него я жду. – Stronger emphasis on the letter from him as the main topic/contrast: It’s a letter from him that I am waiting for (as opposed to something else / someone else).

Meaning doesn’t change drastically; only the focus and information structure shift.

Does жду mean “I wait” or “I am waiting”? How do you express the continuous aspect?

Жду covers both:

I wait (habitual or general)
I am waiting (right now)

Russian doesn’t have a special continuous tense like English am waiting. Context usually makes it clear:

Сейчас я жду письма от него. – Right now I am waiting for a letter from him.
Каждый день я жду письма от него. – Every day I wait for a letter from him.

Both use the same жду, with adverbs or context expressing whether it’s ongoing or habitual.

Can I drop я and just say Жду письма от него?

Yes.

In Russian, subject pronouns (я, ты, он, etc.) are often omitted when the verb ending already shows who the subject is:

Жду письма от него. – [I] am waiting for a letter from him.
Ждёшь письма? – Are [you] waiting for a letter?

You usually keep the pronoun when you need to:

emphasize contrast: Я жду письма, а он нет.
avoid ambiguity in a complex sentence

But in simple, clear contexts, omitting я sounds completely natural.

How do I say “I’m waiting for letters from him” (plural), and why isn’t that also письма?

To clearly express plural, you would normally say:

Я жду писем от него. – I’m waiting for letters from him.

Here писем is genitive plural of письмо.

Why not письма?

Письма can be genitive singular or nominative plural, but:
- After ждать, we do not use nominative, only genitive.
- Жду письма is therefore understood as genitive singular (waiting for a letter).
- For plural, you change to genitive plural: жду писем.

So:

жду письма = waiting for a letter
жду писем = waiting for letters

What’s the difference between ждать, подождать, and дождаться in similar sentences?

All three relate to waiting, but their aspect and nuance differ:

Ждать – imperfective, process of waiting (no result implied)
- Я жду письма от него. – I am (in the process of) waiting for a letter from him.
Подождать – perfective, to wait for a while / for some time
- Я подожду письма от него. – I’ll wait (for a bit / for some time) for a letter from him.
  (Often better as: Я подожду, пока придёт письмо от него.)
Дождаться – perfective, to manage to wait until it finally comes (focus on the successful result)
- Я дождался письма от него. – I (finally) got / lived to see the moment when the letter from him arrived.

So:

Use ждать for the ongoing action.
Use подождать when you want to say “wait a bit / will wait”.
Use дождаться when you are emphasizing that the thing you waited for has finally happened.