Misliš li da će put do jezera dugo trajati?

In Croatian, li is a very common particle used to form a yes/no question.

So:

• Misliš. = You think.
• Misliš li...? = Do you think...?

This is a standard pattern:

• Znaš li...? = Do you know...?
• Imaš li...? = Do you have...?
• Vidiš li...? = Do you see...?

A native English speaker may expect something like Do you think..., but Croatian does not need an extra verb like do here. It just uses the main verb plus li.

Because li normally comes right after the first stressed word, which is often the verb in yes/no questions.

So:

• Misliš li da... = correct
• Li misliš da... = incorrect

This is part of Croatian clitic placement. Small unstressed words such as li and će tend to go in the second position of their clause.

Here da means that and introduces a subordinate clause.

So the structure is:

• Misliš li = Do you think
• da će put do jezera dugo trajati = that the trip/way to the lake will take a long time

This is very similar to English:

• Do you think that it will take a long time?

In Croatian, da is very common after verbs of thinking, knowing, saying, believing, etc.

Examples:

• Mislim da je u pravu. = I think that he/she is right.
• Znam da dolazi. = I know that he/she is coming.

Croatian future tense is often formed with:

• a form of htjeti in its clitic form: ću, ćeš, će, ćemo, ćete, će
• plus the infinitive

Here:

• će trajati = will last / will take

The words are separate because će is an unstressed clitic.

Examples:

• On će doći. = He will come.
• Put će trajati dugo. = The trip will take a long time.

So in your sentence:

• da će put do jezera dugo trajati

the će comes early in the clause, while trajati stays as the infinitive.

This is because će is a clitic, and clitics usually appear near the beginning of the clause, in the second position.

So Croatian prefers:

• da će put do jezera dugo trajati

rather than:

• da put do jezera će dugo trajati

The second version sounds unnatural or incorrect in standard Croatian.

This can feel strange to English speakers because English keeps will directly with the main verb, but Croatian word order follows clitic rules instead.

Jezera is genitive singular of jezero.

You get this form because of the preposition do, which usually takes the genitive.

So:

• jezero = lake (dictionary form, nominative)
• do jezera = to the lake / up to the lake / of the lake, depending on context

In this sentence, put do jezera means the way/trip to the lake.

More examples with do:

• do kuće = to the house
• do grada = to the city
• do škole = to the school

The noun put can mean several related things, depending on context:

• road
• way
• route
• trip/journey

So put do jezera can be understood as:

• the way to the lake
• the trip to the lake
• the route to the lake

Croatian often uses put where English might choose different words depending on context.

A related noun is putovanje, which more specifically means travel or a journey/trip as an event. But put is very natural in a sentence like this.

Because Croatian often does not use a dummy subject like English it.

In English, you say:

• Do you think it will take a long time?

In Croatian, the actual subject is usually named directly:

• će put do jezera dugo trajati
  literally: will the trip to the lake last long

So instead of an empty subject like it, Croatian uses put do jezera as the subject.

Croatian usually leaves out subject pronouns when they are already clear from the verb ending.

• misliš already means you think (singular, informal)

So:

• Misliš li... = Do you think...?

You could add ti for emphasis:

• Misliš li ti da će put do jezera dugo trajati?

But that sounds more emphatic, like:

• Do you think the trip will take a long time?

So the pronoun is normally omitted.

Dugo is an adverb meaning for a long time / long.

It modifies trajati (to last / to take), so:

• dugo trajati = to last long / to take a long time

Examples:

• Sastanak dugo traje. = The meeting lasts a long time.
• Film neće dugo trajati. = The film will not last long.

English often uses take a long time, while Croatian often uses trajati dugo.

Trajati means to last, and Croatian uses it naturally for things that continue for a certain amount of time.

So:

• Put dugo traje.
  literally: The trip lasts long
• natural English: The trip takes a long time

This is a very common Croatian way to express duration.

Yes, trajati is an imperfective verb.

That makes sense because the sentence is about duration, not a single completed event. Imperfective verbs are commonly used when talking about:

• ongoing action
• repeated action
• duration

Since the idea is how long the trip will last, trajati is exactly the right choice.

Yes, many speakers would also say:

• Da li misliš da će put do jezera dugo trajati?

That is also understandable and common in many contexts. However, Misliš li... is often considered more neutral or more standard in careful usage.

So both patterns exist:

• Misliš li da...?
• Da li misliš da...?

As a learner, it is very useful to recognize both.

Inside the clause da će put do jezera dugo trajati, the core parts are:

• će trajati = will last
• put do jezera = subject
• dugo = adverb

So the clause is basically:

• [future marker] + [subject] + [adverb] + [infinitive]

Because of clitic placement, će comes near the beginning:

• da će put do jezera dugo trajati

This may look unusual if you expect English word order, but it is normal in Croatian.

Croatian word order is somewhat flexible, so you can shift emphasis.

For example:

• Misliš li da će put do jezera dugo trajati?
  neutral

• Misliš li da će dugo trajati put do jezera?
  more emphasis on dugo

• Misliš li da će put dugo trajati do jezera?
  this one sounds awkward because do jezera belongs closely with put

So although Croatian word order can move around, some words still strongly belong together as a phrase:

• put do jezera

That phrase is best kept together.