Kesällä helle voi olla kova, kun taas keväällä tulva voi yllättää kaupungin.

In the summer the heat can be intense, whereas in the spring a flood can surprise the city.

Breakdown of Kesällä helle voi olla kova, kun taas keväällä tulva voi yllättää kaupungin.

• olla: to be
• voida: can
• kaupunki: the city
• kesällä: in the summer
• helle: the heat
• kova: intense
• kun taas: whereas
• keväällä: in the spring
• tulva: the flood
• yllättää: to surprise

Questions & Answers about Kesällä helle voi olla kova, kun taas keväällä tulva voi yllättää kaupungin.

Why is it kesällä and keväällä, with the ending -llä, instead of just kesä and kevät?

The ending -lla / -llä here is the adessive case, and in this context it means in (a season / time period).

So:

• kesä = summer
• kesällä = in (the) summer
• kevät = spring
• keväällä = in (the) spring

Finnish often uses the adessive case for:

• times like parts of the day:
  
  • päivällä = in the daytime
  • yöllä = at night
• seasons:
  
  • talvella = in winter
  • syksyllä = in autumn

You could not say *kesässä or *kevässä in this meaning; the adessive -lla/-llä is the idiomatic way to express in summer / in spring when talking about typical conditions.

What is the difference between helle and just saying something like on kuuma or on lämmin?

All of these relate to heat, but in slightly different ways:

• helle is a noun meaning heatwave / very hot weather (especially hot summer weather).
  
  • On helle. = It’s really hot (as in heatwave conditions).
• kuuma is an adjective: hot.
  
  • On kuuma. = It is hot.
• lämmin is an adjective: warm.
  
  • On lämmin. = It is warm.

In the sentence:

• helle voi olla kova = the heat can be intense / severe.

So instead of just saying that it’s hot (on kuuma), the sentence talks about helle as a phenomenon, and describes how strong it can be (kova).

Why is it helle voi olla kova and not just helle on kova?

The verb voi is the 3rd person singular of voida, which means can / may / be able to.

• helle on kova = the heat is severe (stated as a fact, right now or generally).
• helle voi olla kova = the heat can be / may be severe (it is possible, typical, not guaranteed).

In this sentence, the speaker is making a general statement about what can happen in summer, not saying that the heat is definitely severe every summer. That’s why voi olla is more natural here than plain on.

Why is kova placed after olla: helle voi olla kova, and not kova helle voi olla?

Both orders are possible, but they mean different things:

• helle voi olla kova

  • helle = subject
  • olla = to be
  • kova = predicative adjective describing helle
    This is like English the heat can be severe.

• kova helle voi olla
  Here kova becomes an adjective directly modifying the noun: severe heat can be (…), and we are left expecting something after olla (for example: kova helle voi olla vaarallista = severe heat can be dangerous).

So in the original sentence, kova is meant as the complement of olla, not as an attributive adjective before helle, which is why the word order helle voi olla kova is used.

What does kun taas mean, and how is it different from just kun or mutta?

• kun on its own can mean when or because.
  • Kun tulin kotiin, söin. = When I came home, I ate.
• mutta means but.

Kun taas is a fixed phrase that typically means whereas / while on the other hand, and it explicitly marks a contrast between two situations.

In the sentence:

• Kesällä helle voi olla kova, kun taas keväällä tulva voi yllättää kaupungin.
  → In summer, the heat can be intense, whereas in spring, a flood can surprise the city.

You could replace kun taas with mutta in many contexts, but kun taas sounds more clearly contrastive and comparative, like you’re setting two scenarios side by side.

Why does Finnish use the present tense here, even though we’re talking about what can happen in summer or spring (the future)?

Finnish often uses the simple present tense to describe:

• general truths
• typical or habitual situations
• things that are possible at some time (including future)

So:

• Kesällä helle voi olla kova.
  Literally: In summer, the heat can be intense.
  Interpreted: It is typical or possible that in summer the heat becomes intense.

You don’t need a special future tense in Finnish. Context (here: kesällä, keväällä) tells you that we are talking about what may happen at those times.

Why is it keväällä, not keväisin? What is the difference?

Both are possible but slightly different:

• keväällä (adessive singular) = in the spring (in that season / at that time).
  It can refer to a particular spring or springtime in general.
• keväisin = every spring / in springs (habitually).
  It has a stronger feeling of repeated, habitual action.

So:

• Keväällä tulva voi yllättää kaupungin.
  → In spring, a flood can surprise the city (this is a typical possibility in spring).
• Keväisin tulva voi yllättää kaupungin.
  → Every spring, a flood can (tend to) surprise the city.

The original sentence talks about the season in a generic way; keväällä is enough and very natural.

What exactly does tulva mean here, and how is it different from tulvia or tulvii?

• tulva is a noun: a flood.
  • Tulva voi yllättää kaupungin. = A flood can surprise the city.
• tulvia can be:
  • an infinitive verb form of tulvia (to flood / to overflow), or
  • in some contexts, the partitive plural of tulva (floods).
• tulvii is a verb form, 3rd person singular of tulvia:
  • Joki tulvii. = The river is flooding / overflows.

In this sentence, tulva is clearly a singular noun subject: a flood.

Why is kaupungin in that form? What case is it, and why isn’t it just kaupunki?

Kaupungin is the genitive singular of kaupunki (city).

As the object of yllättää (to surprise), kaupungin is a total object: the city as a whole is affected by the action. In Finnish, the total object in the singular often appears in the genitive form.

• tulva voi yllättää kaupungin
  = the flood can surprise the whole city.

If you wanted to express something like only part of the city, or an ongoing, not-completed action, you could see the partitive:

• Tulva voi yllättää kaupunkia.
  (unnatural here, but structurally: affect the city partially / to some extent)

So the genitive kaupungin is the correct total object form in this context.

Could the word order be Kaupungin voi yllättää tulva instead of Tulva voi yllättää kaupungin? Does that change the meaning?

Yes, that word order is grammatically possible:

• Tulva voi yllättää kaupungin.
  Neutral word order: tulva (subject) first, kaupungin (object) after the verb.

• Kaupungin voi yllättää tulva.
  This puts kaupungin into a more emphatic / topicalized position:
  Something like It’s the city that a flood can surprise, or As for the city, it can be surprised by a flood.

The basic meaning (a flood can surprise the city) is the same, but the focus changes. The original word order is more neutral and common in written standard Finnish.

Why is there a comma before kun taas?

In Finnish punctuation, a comma is usually placed between main clauses, and also before certain conjunctions that connect clauses.

Here we have two main clauses:

1. Kesällä helle voi olla kova
2. (kun taas) keväällä tulva voi yllättää kaupungin

They are joined by kun taas, a conjunctional phrase marking contrast. A comma is normally used before such a connector:

• …, kun taas …

So the comma separates the two clauses and introduces the contrast expressed by kun taas.

Finnish has no articles. How do I know whether kesällä and kaupungin mean the summer / the city or a summer / a city?

Finnish does not have articles like a / an / the, so context decides how we translate nouns into English.

• kesällä here is generic: (in) summer, often translated as in the summer when we speak of typical summer conditions.
• kaupungin here refers to the specific, contextually known city (probably the one already being talked about), so in natural English we say the city.

In many general statements about weather and nature, English tends to use the (the sun, the wind, the city), whereas Finnish just uses the bare noun or a case form. So you choose a or the in English based on what sounds natural there, not because of a specific Finnish form.

Is yllättää always used with people, or can you surprise a city as in tulva voi yllättää kaupungin?

Yllättää = to surprise, and it can be used:

• with people:
  • Uutinen yllätti minut. = The news surprised me.
• with groups, organizations, places:
  • Tulva voi yllättää kaupungin. = A flood can surprise the city.
    (Meaning: the city authorities, residents, infrastructure, etc. are caught unprepared.)

So yes, it’s normal and idiomatic to say yllättää kaupungin in this metaphorical sense, just as in English you might say a storm hit the city unexpectedly or a crisis caught the city off guard.