Finnish English Explanation
Hidas kuin etana As slow as a snail Very slow
Ovela kuin kettu As sly as a fox Untrustworthy
Tyhmä kuin aasi As stupid as a donkey Very stupid
Tyhmä kuin saapas As stupid as a boot Very stupid
Iloinen kuin peipponen As happy as a chaffinch Very happy
Epäsiisti kuin sika As untidy as a pig Very dirty
Kuin nuori varsa kesälaitumella Like a young horse in the field Wild and happy
Kuin elefantti lasikaupassa Like an elephant in a china shop Very clumsy
Syödä kuin hevonen To eat like a horse To eat very much
Syödä kuin sika To eat like a pig To eat very messily
Terve kuin pukki As healthy as a billy-goat Very healthy
Kova kuin kivi Hard as a rock Very hard
Kaunis kuin kuva Pretty as a picture Very pretty
Vapaa kuin taivaan lintu Free as the sky's bird Completely free
Rikas kuin Kroisos Rich like the Greek Croisos Very rich
Nopea kuin ajatus Fast as a thought Very fast
Nopea kuin salama Fast as lightning Very fast
Kevyt kuin höyhen Light as a feather Extremely light
Lyhyt kuin kanan lento Short like a chicken's flight Very short
Pitkä kuin nälkävuosi Long as a year of hunger Very long
Köyhä kuin kirkon rotta Poor as a church's rat Very poor
Sinä olet täydellinen lammas You're a perfect lamb You're too scared
Itsepäinen kuin pässi As stubborn as a ram Extremely stubborn
Itsepäinen kuin aasi As stubborn as a donkey Extremely stubborn
Kuuma kuin saunassa Hot like in the sauna Very hot
Pieni kuin pippuri Tiny like a pepper Very tiny

The original list was taken from Wikipedia's "List of idioms in the Finnish language".

"Ensin työ, sitten leikki."
"First work, then play."
You should first do what has to be done, and leave the fun things for later.

"Terve sielu terveessä ruumiissa."
"A healthy soul in a healthy body."
Only by keeping your body healthy you can stay happy as well.

"Lyödä kaksi kärpästä yhdellä iskulla."
"Hit two flies with one hit."
To do two things with the effort of only one.

"Viina on viisasten juoma."
"Strong alcohol is the smart one's drink."
Only wise people should drink alcohol, because they know when to stop.

"Minkä nuorena oppii, sen vanhana taitaa."
"What is learned as a child, is mastered as an old person."
Learning things when you're young is a very good idea.

"Haukkuva koira ei pure."
"The barking dog doesn't bite."
The people who seem the most dangerous in their words are usually the most harmless.

"Älä lyö lyötyä."
"Don't hit a man when he's down."
Play fair.

"Kysyvä ei tieltä eksy."
"The one who asks doesn't get lost from his road."
There's no shame in asking.

"Ei savua ilman tulta."
"No smoke without fire."
There's always something true about rumours.

"Älä osta sikaa säkissä."
"Don't buy a pig in a bag."
Always make sure you know what exactly you are buying.

"Kertaus on opintojen äiti."
"Repetition is learned things' mother."
You learn by repeating things several times.

"Ruokahalu kasvaa syödessä."
"The will to eat grows by eating."
Said to children when they don't want to eat.

"Ottaa härkää sarvista."
"Take the bull by it's horns."
To tackle something even if it's difficult.

"Nostaa kissa pöydälle."
"To lift the cat onto the table."
To start talking about a difficult subject.

"Susi lampaiden vaatteissa."
"A fox in lambs' clothes."
He might seem harmless, but he's hiding something.

"Matkustaa jäniksenä."
"To travel as a rabbit."
To travel without paying the fare.

"Penni ajatuksista"
"A penny for your thoughts."
Tell me what's on your mind.

"Pitää mykkäkoulua."
"To give somebody the silent treatment."
To not talk to somebody.

"Älä herätä nukkuvaa karhua."
"Don't wake a sleeping bear."

"Heittää legendaa."
"To throw legends."
To tell a lot of lies.

"Minulla on matti kukkarossa."
"I am in serious money trouble.""

"Aukoa päätään."
"To open one's head."
To speak provocatively to someone.

"En minä voi siksi muuttua."
"I can't change into that."
A statement that a desired object simply isn't available, no matter how much someone keeps asking for it. The word "siksi" (into that) is substituted with the object in question, in translative "-ksi".

"Ei haukku haavaa tee, jos ei koira purra saa."
"A bark leaves no marks if you don't let the dog bite."

"Ei ole koiraa karvoihin katsominen."
"Judge not the dog by its hair."
"Don't judge a book by its cover."

"Ei kukaan ole seppä syntyessään."
"No one is a blacksmith when they are born."
No one can be an expected to be an expert at something before they have got the chance to practice it.

"Ei olla jäniksen selässä."
"Not to be on the back of a rabbit."
Not to be in an immediate hurry.

"Ei se työtä kun uskaltaa vaikka työn ääreen makaamaan."
"Work doesn't scare him, but he could lay down near it and sleep."

"Ei sylje lasiin."
"Not to spit into the glass."
Not to abstain from alcohol (always used with a negative).

"Ei (tule) lasta eikä paskaa."
"Neither baby, nor shit comes."
To describe an unsuccessful, painful effort.

"Elää kuin pellossa."
"To live as if in a field."
To live without cleaning up after oneself, or bothering about what others think about one.

"Halukas auttaja tulee käskemättä."
"A willing helper comes without asking."

"Happamia, sanoi kettu pihlajanmarjoista."
"Sour said the fox about rowan berries."
Said to someone who says negative things about something he is unable to have, but he probably deep down would like to have.

"By throwing it."
With little or no effort required.

"Heittää veivinsä."
"To throw one's crankshaft"
To die.

"Heittää lusikka nurkkaan."
"To throw the spoon in the corner."
To die.

"Helppoa kuin heinänteko."
"Easy as making hay."
Extremely easy.

"Hyvä sopu sijaa tekee."
"Harmony creates accommodation."

"Joko teet tai itket ja teet."
"Either you'll do it or you'll cry and do it."
A direct order to do something, whether the addressed wants to do it or not. The word "teet" (do it) can be substituted with whatever verb is necessary from context.

"Jumalan selän takana."
"Behind God's back."
In an uninteresting place, or in a place where no one else usually comes. Sometimes implies a disrespect of rural communities.

"Kahden kauppa on kolmannen korvapuusti."
"A good deal for two, is a clip on the ears of a third."
In a trade someone always loses.

"Kasvaa se mies räkänokistakin, vaan ei tyhjän naurajista."
"A snotnose may grow up to be a man; but he who laughs without cause, never."
The mocked may grow up to dignity, but the mocker will never outgrow his juvenile behaviour.

"Katoaa kuin pieru Saharaan."
"Disappears like a fart into Sahara."
Disappears without trace.

"Ken kuuseen kurkottaa, se katajaan kapsahtaa."
"Who reaches for the spruce, falls down onto the juniper."
If you reach for something that is far too good for you, it is not going to end well.

"Kenen leipää syöt, sen lauluja laulat."
"Whose bread you eat, his songs you'll sing."
He who pays the piper calls the tune.

"Kestää ikä ja terveys."
"To take the time of one's age and health."
To take a far too long time, or be of far too much effort.

"Kiertää kuin kissa kuumaa puuroa."
"To circle like a cat circles hot porridge."
To constantly and obviously covet something without actually making a move to get it, or to try to approach a difficult topic of speech in a roundabout way.

"Kiinnostaa kuin kilo paskaa."
"Interests (me) as much as a kilogram of shit."
Doesn't interest at all (or annoys you).

"Koira haudattuna."
"A dog buried here."
An implication that there's something foul behind the scenes, the situation is not what it appears to be.

"In the backwoods."
A place that is somewhere in a area with no interesting things surrounding it.

"Kuin allit kalliolla."
"Like ducks (exactly: a particular species that leaves last in the autumn) on a cliff."
Left by oneself, without outside support.

"Kuin Euroopan omistaja."
"Like someone who owns Europe."
Acting excessively posh and snobby. Usually an implication of misplacen superiority towards others.

"Kuin kaksi marjaa."
"Like two berries."
Two people or things that seem extremely alike.

"Kuin perseeseen ammuttu karhu."
Like a bear which has been shot in the ass."
Being extremely cranky.

"Kuin seipään niellyt."
"As if swallowed a spear."
Standing unnaturally or needlessly upright.

"Kuin tervan juontia."
"Like drinking tar."
Extremely slow, difficult, or ardurous.

"Kuin tuhka tuuleen."
"Like ash in the wind."
Disappeared without trace.

"Kuin viilipytty."
"Like a pot of sour milk."
Very calm.

"Kylmä kahvi kaunistaa."
"Cold coffee makes (you) beautiful."

"Köyhällä ei ole varaa halpaan."
"The poor can't afford to buy cheap."

"Mikä tietoa lisää, se tuskaa lisää."
"What adds to knowledge, adds to pain."
Ignorance is bliss.

"Moni kakku päältä kaunis, vaan on silkkoa sisältä."
"Many cakes are beautiful on the surface, but have crappy fillings."

"Laita lapsi asialle, mene itse perästä."
"Send a child to do your errands, go do them yourself afterwards."
You can't trust that a job will be done properly unless you do it yourself.
Used to reprimand someone who has failed in something, usually not a child.

"Niin makaa, kuin petaa."
"One sleeps like one makes his bed."
Actions have consequences.

"Ojasta allikkoon."
From the ditch to the water jump.

"Olla hukassa."
"Be in a wolf."
Being lost, missing, in despair, perished.

"Oma koti kullan kallis."
Own home is worth gold.

"Oma lehmä ojassa."
"With one's own cow in the ditch."
Having a personal interest or investment in the matter.

"Oma maa mansikka; muu maa mustikka."
"Other land blueberry; own land strawberry."
Foreign places are nice enough, but home is sweeter.

"Parempi pyy pivossa, kuin kymmenen oksalla."
"Better one hazel grouse in the bag, than ten on the branch."
A bird in the hand is worth two in the bush.

"Pata kattilaa soimaa."
"The pot reproaching the kettle."
The pot calling the kettle black.

"Peukalo keskellä kämmentä."
"With one's thumb in the middle of one's palm."
Very bad at doing something, usually manual labour.

"Potkaista tyhjää."
"To kick empty space."
To die.

"Puhtaus on puoli ruokaa."
"Cleanliness is half a meal."
Keeping yourself and your food clean, you'll get more from it. Cleanliness is next to godliness.

"Päästää sammakko suustaan."
"To let a frog out from oneself's mouth."
Blunder, to accidentally say something that shouldn't be said

"Ruista ranteessa."
"Rye in one's wrist."
Physically strong.

"Sataa kuin saavista kaataen."
"It's pouring like from a big bucket."

"Sattuu sitä paremmissakin perheissä."
"Happens in better families too."
Such things happen even to better folk.

"Se koira älähtää, johon kalikka kalahtaa."
"That dog yelps, which (the) stick hits."
It is the dog which is hit by the tossed stick, which yelps.
Said to/about someone who makes a big do about a statement which is thus considered to be apposite.

"Sokerina pohjalla."
"As the sugar at the bottom."
As a final bonus, benefit or gift

"Toimii kuin junan vessa."
"Works like the train toilet."

"Tulla kuin havumajaan."
"To come as if coming into a hut made of tree needles."
To enter a house easily, often against the wishes of the house's owner

"Tumput suorina."
"With one's gloves straight."
Not doing anything, with an implication that one should be doing something.

"Ulkona kuin lumiukko."
"Out like a snowman."
Not to know anything about a given thing and thus be stunned, or to say things that are not relevant to the thing.

"Vesi vanhin voitehista."
"Water is the oldest medicine."

"Vetää jojoon."
"To put in a yo-yo."
To execute by hanging. Almost always used of suicide.

"Vuonna miekka ja kypärä/kivi."
"In the year of sword and helmet/stone."
Very long time ago.

"Yksi tyhmä kysyy enemmän, kuin kymmenen viisasta ehtii vastata."
One stupid person asks more than ten wise ones can spare time answering.

"Älä maalaa pirua seinälle."
"Don't paint the devil [on the] wall. (can also be translated as a demon)"
Don't paint the image of a demon on a wall. A basic admonishment to not agonize unduly about worst case scenarios; they may not happen. Alternatively an expression of a superstititious fear of something uttered coming true (cf. "jinx"; "knock on wood" or "tempting fate").

"Äänellänsä se variskin laulaa."
"Even the crow sings with its own voice."
Express yourself earnestly, and you have no reason for shame even if you lack talent.