Válka trvala dlouho.

The verb trvat means to last, to continue, or to take (time) depending on context. In this sentence, Válka trvala dlouho, it means The war lasted a long time.

So:

• válka = war
• trvala = lasted / was lasting
• dlouho = a long time / for a long time

In natural English, lasted is usually the best translation here.

Because the subject válka is feminine singular.

In the Czech past tense, the main verb agrees with the subject in gender and number. Since válka is feminine singular, the past form is trvala.

Compare:

• válka trvala = the war lasted
• film trval = the film lasted
• město trvalo = the town/city lasted
• boje trvaly = the fights lasted

So the -a ending in trvala shows feminine singular agreement.

In Czech, the past tense is formed differently from English.

With most verbs, Czech uses a past participle-like form. In the 3rd person, there is usually no separate auxiliary word. So:

• trval / trvala / trvalo / trvaly can by themselves mean lasted

That is why Válka trvala dlouho is a complete sentence.

For comparison, in 1st and 2nd person you do see auxiliary forms:

• Trval jsem dlouho. = I lasted / It took me a long time
• Trvala jsi dlouho. = You lasted / It took you a long time

But in the 3rd person, Czech normally leaves that auxiliary out.

Válka is in the nominative singular, because it is the subject of the sentence.

The basic dictionary form is also válka. Here it means war or the war, depending on context.

Since Czech has no articles like a or the, válka can mean:

• a war
• the war
• sometimes even war in a more general sense

The context tells you which is meant.

No. Dlouho is an adverb, not an adjective.

It comes from the adjective dlouhý = long, but here it modifies the verb trvala, so it means:

• for a long time
• a long time

Compare:

• dlouhá válka = a long war
• válka trvala dlouho = the war lasted a long time

So:

• dlouhá = adjective
• dlouho = adverb

Because after trvat in this sentence, Czech uses an adverb of duration, not an adjective.

So you say:

• trvat dlouho = to last a long time

You can also use a noun phrase:

• trvat dlouhou dobu = to last a long time
  
  • here dlouhou is an adjective agreeing with dobu

But in Válka trvala dlouho, there is no noun after it, so the adverb dlouho is correct.

Trvat is imperfective.

That makes sense because lasting describes a process or duration, not a single completed event viewed as a whole. Czech often uses imperfective verbs when talking about how long something continued.

So Válka trvala dlouho focuses on the duration of the war.

A native English speaker may expect some kind of perfective past because English says lasted, but Czech aspect works differently. Here the natural verb is trvat, which is imperfective.

Yes. Czech word order is more flexible than English, because case endings and verb forms carry a lot of grammatical information.

The neutral order here is:

• Válka trvala dlouho.

But you could also say:

• Dlouho trvala válka.
• Trvala dlouho válka.
  This is possible, but it sounds marked and depends heavily on context.

Different word orders can shift emphasis:

• Válka trvala dlouho. = neutral statement
• Dlouho trvala válka. = emphasis on how long

English usually cannot do this as freely.

A rough pronunciation guide:

• Válka ≈ VAAL-ka
• trvala ≈ TR-va-la
• dlouho ≈ DLOU-ho

A few useful points:

• Czech stress is usually on the first syllable of each word.
• á is a long vowel.
• ou is a diphthong, somewhat like the ow in go
  • oo, but smoother.
• The cluster trv- in trvala can feel difficult for English speakers because Czech allows consonant-heavy combinations.

It can mean either, depending on context.

Because Czech has no articles, válka can correspond to:

• war
• a war
• the war

So if the surrounding context is about a specific historical war, then Válka trvala dlouho can mean The war lasted a long time. If the context is more general, it could also mean A war lasted a long time or even War lasted a long time, though that last one is less likely in English.

It is similar, but not exactly the same.

• Válka trvala dlouho. = The war lasted a long time.
  This focuses on duration as an event/process.

• Válka byla dlouhá. = The war was long.
  This describes the war with an adjective.

Both are correct, but trvala dlouho is often the more natural way to talk about how long something continued.

The dictionary forms are:

• válka = war
• trvat = to last
• dlouho = for a long time / long (as an adverb)

The form trvala is not the dictionary form; it is the past tense feminine singular form of trvat.

Yes, very commonly. This is a very useful pattern in Czech.

Examples:

• Schůze trvala dlouho. = The meeting lasted a long time.
• Cesta trvala dlouho. = The journey took a long time.
• Film trval dlouho. = The film lasted a long time.
• Jednání trvalo dlouho. = The negotiations lasted a long time.

So trvat dlouho is a common structure for talking about duration.