Learn Hardcore Russian: Летом нам хочется сидеть на террасе кафе и смотреть, как люди идут по улице. - In summer we feel like sitting on the café terrace and watching people walk along the street.

So «летом» already means “in summer” by itself.
Using «в лето» or «в летом» is incorrect in standard modern Russian when you just mean in summer (generally).

What exactly does «нам хочется» mean, and why is «нам» in the dative case?

«Хочется» is the impersonal verb «хотеться» (to feel like, to be in the mood for something).
In impersonal constructions, the experiencer (the person who feels something) is put in the dative case:

мне хочется – I feel like / I want (in an emotional, soft way)
тебе хочется – you feel like
нам хочется – we feel like

So «нам» is dative plural of мы (we).
The literal structure is something like: “It is wanted to us to sit … and watch …” → naturally translated as “We feel like sitting … and watching …”.

This is softer and more emotional than «мы хотим» (“we want”), which sounds more direct and sometimes less “dreamy” or less polite.

What is the difference between «нам хочется» and «мы хотим» here?

Both can be translated as “we want”, but the nuance is different:

мы хотим сидеть на террасе кафе…
– plain statement of desire, neutral, more “volitional”.
нам хочется сидеть на террасе кафе…
– emphasizes a spontaneous feeling / mood / craving.
– sounds softer, more emotional, more atmospheric, which fits well with talking about summer, terraces, and people-watching.

So in this sentence «нам хочется» adds a relaxed, dreamy tone: “In summer, we feel like sitting on a café terrace…”, not just “we want” as a hard decision.

Why is «хочется» in 3rd person singular neuter (ending in -ется) when the subject seems to be “we”?

Because «хочется» is used in an impersonal construction. There is no grammatical subject like “we” or “I” in the nominative.

Verb form: хочется – 3rd sg. neuter, impersonal
Experiencer: нам (dative), not a grammatical subject

Russian often uses third-person singular neuter to talk about impersonal states:

мне холодно – I’m cold (literally: to me it-is-cold)
ему грустно – he is sad (to him it-is-sad)
нам хочется сидеть… – we feel like sitting… (to us it-is-wanted-to-sit)

So grammatically «хочется» behaves like “it is wanted / one feels like” rather than “we want”.

Why are «сидеть» and «смотреть» in the infinitive form?

In Russian, after «хотеться» (or «хотеть») you normally use an infinitive to express what you want to do:

мне хочется спать – I feel like sleeping
нам хочется сидеть и смотреть – we feel like sitting and watching

Both infinitives (сидеть, смотреть) depend on the same «хочется»:

нам хочется [сидеть …] и [смотреть …]

That is: “We feel like to sit on the café terrace and to watch how people walk along the street.”

Why is it «сидеть» and not «сесть»?

Both come from сидеть / сесть (to sit / to sit down), but:

сидеть – imperfective, describes the state / process of sitting (being seated).
сесть – perfective, the action of sitting down (the moment you sit).

In the sentence, the idea is not “we want to sit down (right now)” but “we want to be sitting there (spending time in that state).”
So «хочется сидеть» = “we feel like (being) sitting,” focusing on enjoying the state over time, not on the single act of sitting down.

How is «на террасе кафе» structured grammatically? Which cases are used?

Phrase: на террасе кафе

террасе – prepositional case of терраса (terrace):
- на террасе = “on the terrace / at the terrace” (location → prepositional after на).
кафе – indeclinable noun (stays кафе in all cases). Here it is in genitive meaning “of the café”, but it looks the same as the nominative.

The whole phrase literally is: “on the terrace of the café” → natural English: “on a café terrace / at a café terrace.”

Word-by-word:

сидеть на террасе кафе – “to sit on the café’s terrace.”

Why is «кафе» unchanged while «терраса» becomes «террасе»?

«Кафе» is an indeclinable noun (often foreign words ending in -e are like that). It does not change form for case or number:

это кафе – this café
в кафе – in the café
у кафе – by the café
терраса кафе – the terrace of the café

«Терраса», however, is a regular feminine noun:

терраса – nominative (subject form)
на террасе – prepositional (after на for “on, at” with location)

So only “терраса” changes its ending here; “кафе” stays the same.

What does «как» mean in «смотреть, как люди идут по улице»?

Here «как» introduces a subordinate clause that is the object of «смотреть»:

смотреть, как люди идут по улице
→ literally: to watch how people walk along the street
→ natural English: to watch people walk along the street

So «как» here is close to “how / as”, but in English we often drop the word “how” in this kind of object clause.

Why is there a comma before «как»?

In Russian, subordinate clauses are usually separated from the main clause by a comma.

Main part: смотреть (to watch)
Subordinate clause: как люди идут по улице (how people are walking along the street)

So you write a comma:
…и смотреть, как люди идут по улице.

This is required by standard Russian punctuation rules: a comma before «как» when it begins a subordinate clause (unless «как» is part of a set phrase where the comma is not used, which is not the case here).

Why is it «идут» and not «ходят»?

Both come from идти / ходить (to go, to walk), but they differ:

идти (uni-directional, imperfective): movement in one direction, usually seen as one ongoing process – “to be going / walking (now).”
- люди идут по улице – people are walking along the street (right now, in front of us).
ходить (multi-directional, imperfective): repeated / habitual movement or movement back-and-forth.
- люди ходят по улице can suggest “people (in general) walk on the street” or habitual movement.

In this sentence, we are watching the current flow of people passing by, so «идут» (one-direction, ongoing movement) is more natural.

What does «по улице» mean exactly, and what case is «улице»?

«По улице» literally means “along the street / down the street / in the street (moving around)”.

по
- dative often indicates movement within or along a surface / area:
  - гулять по парку – to walk around the park
  - идти по дороге – to go along the road
  - идут по улице – they are walking along the street

«Улица» in the dative singular is «улице».
So «по улице» = “along the street” with улице in the dative case.