Когда мне хочется отдохнуть, я рисую в альбоме у окна.

Мне хочется is a very common Russian way to say I feel like... or I have a desire to...

There is a difference in tone:

• я хочу отдохнуть = I want to rest
• мне хочется отдохнуть = I feel like resting / I kind of want to rest

So хочется often sounds softer, more about an internal feeling or urge, rather than a direct statement of will.

Because хочется is used in an impersonal construction.

Literally, Russian is expressing something like:

• To me, it is wanted
• or more naturally: I feel like...

In these impersonal patterns, the person experiencing the feeling often appears in the dative:

• мне холодно = I am cold
• мне нравится = I like
• мне хочется = I feel like

So мне does not mean to me in a fully literal English sense, but grammatically that is how Russian builds the sentence.

Хочется is the 3rd person singular form of хотеться, which is related to хотеть.

Compare:

• хотеть = to want
• хотеться = to feel like wanting / to have the urge

In practice:

• я хочу спать = I want to sleep
• мне хочется спать = I feel sleepy / I feel like sleeping

So in your sentence, хочется is not agreeing with я. It is part of an impersonal structure, which is why it stays in the neuter-like 3rd person singular form.

Because отдохнуть is the perfective infinitive.

Here the speaker means to get some rest, seen as a complete result or a single whole action. That is why perfective works well.

• отдохнуть = to rest, to have a rest, to become rested
• отдыхать = to be resting, to rest in general, to rest repeatedly

With хочется, both aspects are possible, but they give slightly different shades:

• мне хочется отдохнуть = I feel like having a rest
• мне хочется отдыхать = I feel like resting / I feel like spending time resting

In this sentence, отдохнуть sounds more natural because the idea is when I feel like taking a break.

Because Когда мне хочется отдохнуть is a subordinate clause introduced by когда.

Russian, like English, separates this kind of clause with a comma:

• Когда мне хочется отдохнуть, я рисую...
• When I feel like resting, I draw...

The comma is required in standard Russian punctuation.

It can feel like either, depending on context.

In a sentence like this, it often has a habitual meaning:

• Когда мне хочется отдохнуть, я рисую...
• When/Whenever I feel like resting, I draw...

Because the main verb рисую is present tense and suggests a repeated habit, English whenever is often a good interpretation, even though Russian still simply uses когда.

Рисую is imperfective, and that fits the meaning here: the speaker is describing a habit or a general repeated action.

• рисую = I draw / I am drawing
• нарисую = I will draw / I will finish drawing

So here:

• я рисую = I draw
• meaning: this is what I do when I feel like resting

If you said я нарисую, it would sound like a future completed action, which does not match the idea of a regular habit.

В альбоме is the prepositional case.

The preposition в can take different cases depending on meaning:

• в + accusative = motion into somewhere
• в + prepositional = location in/inside somewhere

Here there is no motion; it means the drawing is being done in the album/sketchbook:

• в альбоме = in the album / in the sketchbook

So:

• альбом → dictionary form
• в альбоме → prepositional singular

In Russian, альбом can mean several kinds of albums, depending on context:

• photo album
• music album
• drawing pad / sketchbook

Because the verb is рисую, the listener naturally understands альбом here as a drawing album, sketchbook, or pad for drawing.

So рисую в альбоме means something like:

• I draw in my sketchbook
• I draw in a drawing pad

Russian does not always need a special separate word where English might prefer one.

Because the meaning is in the album/sketchbook, not on top of the album.

Compare:

• рисовать в альбоме = to draw in a sketchbook / on the pages of the album
• рисовать на альбоме = to draw on the outside surface of the album

Russian chooses the preposition based on how the object is conceptualized. A notebook, book, or album is often treated as a space you work in, not just a surface you work on.

У окна means by the window, near the window, or next to the window.

The preposition у usually means by / beside / near, and it requires the genitive case.

So:

• окно = window
• у окна = by the window

It describes location, probably where the speaker is sitting or where the album is.

Because the preposition у requires the genitive.

This is simply a rule you have to learn with the preposition:

• у дома = by the house
• у двери = by the door
• у окна = by the window

So:

• окно → nominative singular
• окна → genitive singular after у

In normal understanding, у окна describes the whole situation of drawing: the speaker is drawing by the window.

Most naturally, English would take it as:

• I draw in a sketchbook by the window

That usually means I am by the window while drawing.

Grammatically, Russian often allows this kind of phrase to attach fairly loosely to the whole clause. It does not have to refer only to the nearest noun.

Yes. Russian word order is flexible, though the neutral version here is perfectly natural.

Your sentence:

• Когда мне хочется отдохнуть, я рисую в альбоме у окна.

Possible variants:

• Я рисую в альбоме у окна, когда мне хочется отдохнуть.
• Когда мне хочется отдохнуть, у окна я рисую в альбоме.

These alternatives may slightly change emphasis, but the basic meaning stays the same.

Russian word order often reflects focus and style, not just grammar.

Yes, in a sense. This is an impersonal sentence, so there is no normal subject like я.

Russian does this often with feelings, states, and experiences:

• мне грустно = I am sad
• мне не спится = I can't sleep / I don't feel like sleeping
• мне хочется отдохнуть = I feel like resting

So although English says I, Russian does not need a nominative subject here. The person affected is shown in the dative: мне.

Yes, absolutely. That would also be correct, but the nuance changes.

• Когда я хочу отдохнуть, я рисую... = When I want to rest, I draw...
• Когда мне хочется отдохнуть, я рисую... = When I feel like resting, I draw...

The version with мне хочется sounds a bit softer, more personal, and more natural in many everyday situations. A native speaker might prefer it when talking about mood or inclination rather than a firm decision.

It is in the present tense, but it expresses a general habit.

• хочется = present
• рисую = present

Even though it is present tense, the meaning is not necessarily right now. It is more like:

• Whenever I feel like resting, I draw in my sketchbook by the window.

Russian present tense often works this way for repeated or typical actions.