Learn Hardcore Finnish: Ensi vuonna haluan työskennellä enemmän kotona.

ensi vuosi = next year as a subject or standalone noun (e.g. Ensi vuosi on tärkeä. – Next year is important.)
ensi vuonna = in next year → idiomatic English next year when it’s an adverbial of time.

In your sentence, ensi vuonna functions as a time expression (when?), so the inessive vuonna is used instead of nominative vuosi.

Could the sentence start with Haluan instead of Ensi vuonna? Is the word order flexible?

Yes, Finnish word order is quite flexible. You can also say:

Haluan työskennellä enemmän kotona ensi vuonna.

Both versions are correct. The difference is mostly in emphasis:

Ensi vuonna haluan… puts emphasis on next year (contrast with other years).
Haluan… ensi vuonna. puts the focus first on the want, and the time comes as added information.

All of these are natural, with only slight shifts in emphasis.

Why is there no minä in the sentence? How do I know it means “I”?

Finnish usually omits personal pronouns when the verb ending already shows the person.

haluan = I want (1st person singular ending -n)
haluat = you want
hän haluaa = he/she wants

So minä is not needed: (Minä) haluan työskennellä….
You can include minä for emphasis or contrast: Minä haluan työskennellä enemmän kotona (I want to work more at home, as opposed to someone else).

What tense is haluan? How can it talk about the future?

Haluan is present tense. Finnish doesn’t have a separate future tense like English.

Future meaning is normally expressed with the present tense plus context:

Huomenna menen töihin. – I will go to work tomorrow.
Ensi vuonna haluan työskennellä… – Next year I want to work…

The time word (ensi vuonna) tells you that the action is in the future.

What is the difference between haluan and haluaisin here?

Both can appear in this sentence, but they sound different:

Haluan työskennellä enemmän kotona.
– direct, factual: I want to work more at home.
Haluaisin työskennellä enemmän kotona.
– more polite / tentative / wishful: I would like to work more at home.

So you’d use haluan when simply stating a clear desire, and haluaisin when being softer or more polite, especially in conversation with others.

Why is työskennellä in this form? Is it an infinitive?

Yes. Työskennellä is the basic (1st) infinitive form of the verb työskennellä (to work).

After verbs like haluta (to want), Finnish uses this infinitive:

Haluan nukkua. – I want to sleep.
Haluan syödä. – I want to eat.
Haluan työskennellä. – I want to work.

The personal form would be (minä) työskentelen (I work), but after haluan you must use the infinitive työskennellä, not työskentelen.

Could I say Haluan tehdä töitä enemmän kotona instead of työskennellä? Is there a difference?

Yes, you can say that, and it’s natural:

Haluan työskennellä enemmän kotona.
Haluan tehdä töitä enemmän kotona.

Both mean almost the same (I want to work more at home), but:

työskennellä is a single verb meaning “to work (as in have a job / perform job duties)”.
tehdä töitä literally = “to do work / do jobs”, slightly more colloquial but very common.

In many everyday contexts they’re interchangeable.

What does enemmän literally mean? Is it related to paljon?

Enemmän means “more” (a larger amount). It’s the comparative form that corresponds to paljon (a lot, much).

paljon – a lot / much
enemmän – more
eniten – most

Your sentence contrasts the amount of working: to work more (than before / than now). If you make the comparison explicit, you get:

Haluan työskennellä enemmän kotona kuin toimistossa.
– I want to work more at home than at the office.

Can I change where enemmän appears in the sentence?

You have some freedom, but not all positions sound equally natural. These are good:

Haluan työskennellä enemmän kotona.
Haluan työskennellä kotona enemmän. (emphasis on “at home”)

This one is possible but slightly less natural in neutral speech:

Haluan enemmän työskennellä kotona.

More typical is verb + enemmän + place or verb + place + enemmän.
Placing enemmän directly before haluan would change the meaning (I more want…), so that’s a different structure.

Why is it kotona and not kotiin or just koti?

Finnish uses different forms of koti to express location and movement:

kotona – at home (where something happens; inessive, static location)
kotiin – (to) home (movement towards; illative)
kotoa – from home (movement away; elative)
bare koti is usually the basic dictionary form, used in some expressions, but not for “at home”.

Your sentence describes where you want to work (a static place), so kotona (at home) is the correct form:
…työskennellä enemmän kotona. – to work more at home.

Could I say Ensi vuosi haluan työskennellä enemmän kotona?

No, not like that. Ensi vuosi in nominative would be interpreted as a subject: Next year (does something).

You need either:

Ensi vuonna haluan työskennellä enemmän kotona. (In next year I want…)
or, if you really want ensi vuosi as a subject, a different structure:
Ensi vuosi on vuosi, jolloin haluan työskennellä enemmän kotona.
– Next year is the year when I want to work more at home.

For a simple sentence, always use ensi vuonna for next year as a time adverbial.

How would I turn this into a question: “Do you want to work more at home next year?”

You keep the same structure, change person, and add the question ending:

Haluatko työskennellä enemmän kotona ensi vuonna?

Breakdown:

haluat = you want
-ko = yes/no question particle attached to the verb
rest of the sentence stays the same.

So the basic pattern is: Haluatko + infinitive + extra information?