Learn Hardcore Finnish: Tiskisieni haisee pahalta, joten heitän sen pois ja otan uuden. - The dish sponge smells bad, so I throw it away and take a new one.

Finnish commonly forms compounds as a single word, where the first part specifies the type/purpose of the second part. So tiskisieni = a sponge used for dishwashing.

Why is it haisee pahalta and not something like haisee pahasti?

With sensory verbs like:

haista (to smell)
maistua (to taste)
tuntua (to feel)
näyttää (to look)
kuulostaa (to sound)

Finnish often uses an adjective in the ablative case (-lta/-ltä) to express “it seems/smells/tastes like X”:

haisee pahalta = smells bad (literally “smells from bad” → “gives a bad smell impression”)

pahasti is an adverb meaning badly (in the sense of in a bad way), and it doesn’t fit this sensory-judgment pattern as naturally as pahalta.

What case is pahalta, and what is it doing in the sentence?

pahalta is ablative singular of paha (bad): paha → pahalta.

Function: it’s a common complement with sensory verbs, expressing the perceived quality:

Se haisee pahalta. = It smells bad.
Tämä näyttää hyvältä. = This looks good.

So pahalta isn’t an object; it’s describing the “impression” the smell gives.

Why does Finnish use joten here, and how is it different from koska?

joten = so / therefore (introduces a consequence/result)
koska = because (introduces the reason/cause)

In your sentence:

Tiskisieni haisee pahalta, joten... = The sponge smells bad, so... (result follows)

If you used koska, you’d flip the logic:

Heitän sen pois, koska se haisee pahalta. = I throw it away because it smells bad.

Why is the subject minä (I) not written before heitän and otan?

Finnish usually drops personal subject pronouns because the verb ending already shows the person:

heitän = I throw
otan = I take

You can add minä for emphasis or contrast:

...joten minä heitän sen pois... = ...so I (as opposed to someone else) throw it away...

Why is it heitän sen pois—what is pois doing?

pois is an adverb meaning away. It commonly pairs with verbs of removing/discarding:

heittää pois = to throw away
ottaa pois = to take away/remove
laittaa pois = to put away

So heitän sen pois is a natural “verb + particle/adverb” combination, similar to English throw away.

Why is the sponge sen and not sitä?

This is the Finnish object case choice (often taught as total object vs partial object):

sen = total object (completed action / whole item)
sitä = partial object (ongoing/incomplete action, or an unbounded amount)

Here, heitän sen pois implies you throw the whole sponge away as a completed act → sen.

If you said heitän sitä, it could sound like you’re throwing it (around) or doing something not clearly “complete / away”.

Why is it otan uuden and not otan uusi or otan uutta?

Two things are happening:

1) uusi must agree in case with the (implied) noun (tiskisienen) “a new (one)”, so it’s inflected:

uusi → uuden

2) otan uuden uses the total object form (genitive-looking singular), because you’re taking one whole new sponge (a complete, countable item).

otan uutta would be partitive and would usually mean something like:

taking some (amount of) something new, or
an action not presented as a complete “one item taken”

What does uuden refer to—why isn’t tiskisienen repeated?

Finnish often omits a repeated noun when it’s obvious from context, like English a new one.

So otan uuden is understood as:

otan uuden (tiskisienen) = I’ll take a new (dish sponge).

Is the tense present or future here? It looks like present tense in Finnish.

It’s present tense forms:

haisee (smells)
heitän (I throw)
otan (I take)

Finnish often uses the present tense to talk about a near-future or intended action when the context makes it clear—similar to English “It smells bad, so I’m throwing it away and getting a new one.”

Could the word order change, and would it affect the meaning?

Yes, Finnish word order is flexible, but changes emphasis.

Neutral/default:

Tiskisieni haisee pahalta, joten heitän sen pois ja otan uuden.

You could emphasize the object:

...joten sen heitän pois... = ...so it, I throw away... (contrast/emphasis)

Or emphasize the consequence:

...joten pois heitän sen... is possible but more marked/stylistic.

In normal everyday Finnish, the original order sounds natural and neutral.