Kannattaako tämä vanha pyörä kunnostaa?

Kannattaako comes from the verb kannattaa, which often means to be worth it, to be advisable, or to make sense to do something.

It is built like this:

• kannattaa = is worth / is advisable
• -ko / -kö = a question particle used to make a yes/no question

So:

• Kannattaa. = It’s worth it.
• Kannattaako? = Is it worth it?

In this sentence, kannattaako ... kunnostaa? means Is it worth restoring/fixing up ... ?

Finnish often does not use a dummy subject like English it.

In English, you say:

• Is it worth restoring this old bike?

But in Finnish, kannattaa works without needing a separate it. So Finnish simply says:

• Kannattaako tämä vanha pyörä kunnostaa?

A more literal English-style breakdown would be something like:

• Worth-it-Q this old bike restore?

That sounds strange in English, but it is normal in Finnish.

Kunnostaa is the basic dictionary form of the verb, the first infinitive.

After kannattaa, Finnish commonly uses an infinitive:

• kannattaa tehdä = it is worth doing
• kannattaa ostaa = it is worth buying
• kannattaa kunnostaa = it is worth restoring

So in this sentence:

• Kannattaako tämä vanha pyörä kunnostaa?
• literally: Is this old bike worth restoring?

As for word order: Finnish is more flexible than English. Putting kunnostaa at the end is very natural here.

Here, tämä vanha pyörä is in the nominative form:

• tämä = this
• vanha = old
• pyörä = bike

So:

• tämä vanha pyörä = this old bike

With kannattaa in this kind of subjectless construction, it is normal for the object to appear in the nominative form.

Also notice agreement:

• tämä matches pyörä
• vanha also matches pyörä

If the phrase were in another case, all the words would change together, for example:

• tämän vanhan pyörän = of this old bike / this old bike in a different grammatical role

But in your sentence, tämä vanha pyörä is the correct form.

Yes. Pyörä can mean:

• bicycle / bike
• wheel

Context tells you which meaning is intended.

In the sentence Kannattaako tämä vanha pyörä kunnostaa?, the most natural meaning is this old bike, not this old wheel.

This is a very useful vocabulary question.

• korjata = to repair / fix
• kunnostaa = to restore / refurbish / renovate / fix up

So kunnostaa often suggests bringing something back into good condition, maybe with more work than just fixing one problem.

For example:

• korjata pyörä = fix the bike
• kunnostaa pyörä = restore or refurbish the bike

In your sentence, kunnostaa suggests more than a quick repair. It sounds like the bike is old and may need proper restoration.

Yes. Finnish word order is fairly flexible.

You could also say:

• Kannattaako kunnostaa tämä vanha pyörä?

Both are natural, but the emphasis changes a little.

• Kannattaako tämä vanha pyörä kunnostaa?
  This puts this old bike earlier, so it feels a bit more like As for this old bike, is it worth restoring?

• Kannattaako kunnostaa tämä vanha pyörä?
  This feels a bit more neutral: Is it worth restoring this old bike?

Both are correct.

Finnish often makes yes/no questions by attaching -ko / -kö to the first important word, very often the verb.

So:

• Kannattaa. = It’s worth it.
• Kannattaako? = Is it worth it?

This is different from English, where you usually change word order:

• It is worth it.
• Is it worth it?

In Finnish, the question particle does that job.

Finnish vowel harmony controls whether the question particle is -ko or -kö.

• Use -ko with back vowels: a, o, u
• Use -kö with front vowels: ä, ö, y

Since kannattaa contains a, it takes -ko:

• kannattaa + ko = kannattaako

Compare:

• Onko? = Is there / is it?
• Näkyykö? = Is it visible? / Can it be seen?

A few natural answers are:

• Kyllä, kannattaa. = Yes, it is.
• Ei, ei kannata. = No, it isn’t.
• Kyllä, se kannattaa kunnostaa. = Yes, it’s worth restoring it.
• Ei, sitä ei kannata kunnostaa. = No, it’s not worth restoring it.

Notice:

• se = it
• sitä = it in a different case, often used in negative sentences like ei kannata

Yes, very common.

The pattern:

• Kannattaako + noun + infinitive?

is a normal way to ask whether doing something is worthwhile.

For example:

• Kannattaako tämä auto ostaa? = Is this car worth buying?
• Kannattaako tämä kirja lukea? = Is this book worth reading?
• Kannattaako vanha talo remontoida? = Is an old house worth renovating?

So your sentence is a very useful model to learn.