Learn Hardcore Finnish: Netti on jumissa tänään.

It covers things like your home internet connection, mobile data, Wi‑Fi, etc.
It’s very normal in speech and casual writing: Netti ei toimi = “The internet doesn’t work.”

You can also see:

internet (often lower‑case) – a bit more neutral/formal
Internetti – exists, but is less common and can sound a bit clunky or old‑fashioned

In everyday talk, netti is by far the most common word.

Why is there no word for “the” before netti?

Finnish has no articles at all – no “a/an” and no “the”.

So:

Netti on jumissa tänään.
literally: Internet is stuck today.
but in natural English: The internet is stuck today.

Whether English would use “the”, “a”, or no article is something you just have to infer from context when translating from Finnish.

What does jumissa mean literally? Why translate it as “stuck / frozen / jammed”?

Jumissa comes from the noun jumi:

jumi = a jam, a block, something stuck (like a machine jam or muscle knot)
jumissa = “in a jam / in a stuck state” (inessive form: “in jumi”)

With olla (“to be”), olla jumissa is an idiomatic expression meaning:

to be stuck
to be jammed
to be frozen / not responding
not functioning properly

So:

Netti on jumissa.
literally: “The internet is in a jam.”
idiomatically: “The internet is stuck / frozen / not working (properly).”

Is jumissa an adjective, an adverb, or a noun form?

Form‑wise, jumissa is the inessive case of the noun jumi:

jumi (basic form, nominative)
jumissa (“in jumi” → “in a jam / in a stuck state”)

Function‑wise, in this sentence it acts as a predicative complement (the part that says what the subject “is”):

Netti (subject)
on (verb “to be”)
jumissa (what the subject is → “stuck / jammed”)

So grammatically it’s a case‑marked noun used in a predicative way, but you can think of it as working like an adjective here.

Why do we say Netti on jumissa instead of a verb like “break” or “not work”?

Finnish often expresses temporary states with olla (“to be”) plus some complement.

Here are a few very common ways to complain about the internet:

Netti on jumissa.
“The internet is stuck / frozen / jammed.”
Netti ei toimi.
“The internet doesn’t work / isn’t working.”
Netti on hidas.
“The internet is slow.”

Netti on jumissa emphasizes that it’s kind of “hung” or “frozen” – pages don’t load, connections hang, etc.
Netti ei toimi is more general: simply “it doesn’t work.”

Can I change the word order? For example, Tänään netti on jumissa?

Yes. All of these are possible, but the nuance / emphasis shifts:

Netti on jumissa tänään.
Neutral; focus is first on the net being stuck, then you add today.
Tänään netti on jumissa.
Emphasizes today: “Today, the internet is stuck.” (Maybe unlike other days.)
Netti tänään on jumissa.
Grammatically possible but feels marked/stylistic; you’d mainly hear 1 or 2 in normal speech.

Default everyday choice: Netti on jumissa tänään. or Tänään netti on jumissa.

What is tänään exactly? Is it related to tämä (“this”)?

Tänään is an adverb meaning “today”.

It’s historically related to tämä (“this”) and tänä (päivänä) (“on this day”), but for practical learning you can just memorize it as a standalone adverb:

tänään = today
eilen = yesterday
huomenna = tomorrow

In the sentence, tänään is a simple time adverbial: it tells when the net is stuck.

Could this sentence mean that only my Wi‑Fi is stuck, not the whole internet?

Yes, context decides how broad netti is.

Often netti in speech just means “my connection / the connection I’m trying to use”:

If you’re at home, Netti on jumissa tänään. usually means “My home internet/Wi‑Fi is acting up today.”
At work, it likely means the office network.
In a general discussion, it might refer to the wider internet in your area.

So netti can mean the global internet or just “the internet connection I care about right now.”

Is Netti on jumissa tänään formal or informal? Where can I use it?

It’s informal / neutral spoken language:

Perfect for chatting with friends, family, colleagues.
Fine in casual written contexts (messages, social media, internal work chat).

In a very formal context (e.g. a service interruption notice), you’d use something like:

Internet-yhteydessä on tänään häiriöitä.
“There are disruptions in the internet connection today.”
Internet-yhteys ei toimi normaalisti tänään.
“The internet connection is not functioning normally today.”

How would I say “The internet is down again today” in Finnish, using the same structure?

You can build on the same pattern:

Netti on taas jumissa tänään.
= “The internet is stuck again today.”

Or, a bit more natural (Finns often put taas earlier):

Taas netti on jumissa tänään.
“Again, the internet is stuck today.”

In very casual speech, you might also hear:

Netti on taas jumissa.
and the “today” is understood from context.