Ĉu la akvotubo iam likis?

Ĉu is the standard Esperanto particle for a yes/no question.

So:

• La akvotubo iam likis. = The water pipe leaked at some time / has leaked before.
• Ĉu la akvotubo iam likis? = Did / has the water pipe ever leak?

Unlike English, Esperanto does not usually make this kind of question by changing word order or adding do/does/did/has/have. It simply puts ĉu at the front.

Because Esperanto normally keeps the basic statement structure and just adds ĉu to mark a yes/no question.

English:

• The pipe has leaked.
• Has the pipe leaked?

Esperanto:

• La tubo likis.
• Ĉu la tubo likis?

So Esperanto does not usually invert the verb and subject the way English does.

Akvotubo is a compound word:

• akvo = water
• tubo = tube, pipe

Together, akvotubo means water pipe.

This is very common in Esperanto: you combine roots directly to make a more specific word. The final part is usually the main idea, so akvotubo is a kind of tubo.

Esperanto often forms compound nouns as a single word. That is one of the language’s most regular features.

So:

• akvotubo = water pipe
• literally, a pipe for water or water-related pipe

You could sometimes express the same idea in a longer way, such as tubo por akvo, but the compound akvotubo is more natural and compact.

La is the definite article, meaning the.

So:

• la akvotubo = the water pipe

Esperanto has only one article, la, and it does not change for gender, number, or case in normal use.

Also, Esperanto has no indefinite article. So akvotubo by itself could mean a water pipe or just water pipe, depending on context.

Iam basically means at some time.

In a question like this, it is naturally translated as ever:

• Ĉu la akvotubo iam likis? = Has the water pipe ever leaked?

A useful comparison:

• iam = ever / sometime
• neniam = never
• ĉiam = always

So if you asked:

• Ĉu la akvotubo neniam likis?
  that would mean something like Has the water pipe never leaked?

Likis is the past tense of liki:

• liki = to leak
• likis = leaked / did leak

The ending -is always marks past tense in Esperanto.

Examples:

• likas = leaks / is leaking
• likis = leaked
• likos = will leak

Because Esperanto usually uses its simple tense system more directly than English does.

English often distinguishes between:

• Did it leak?
• Has it ever leaked?

Esperanto often uses the plain past tense -is for both kinds of ideas when the context makes the meaning clear.

So:

• Ĉu la akvotubo iam likis?

can naturally correspond to English:

• Did the water pipe ever leak?
• Has the water pipe ever leaked?

The word iam helps create that ever / at any time before now sense.

Yes. Here liki means to leak, with the pipe as the thing that leaks.

So:

• La akvotubo likis. = The water pipe leaked.

There is no direct object in this sentence. That is why you do not see an accusative -n ending on anything.

Because there is no direct object here.

• la akvotubo is the subject
• likis is the verb
• iam is an adverb

The sentence is simply saying that the water pipe performed the action of leaking.

If there were a direct object, you would normally see -n on it, but this sentence does not have one.

Yes. Esperanto word order is fairly flexible, especially with adverbs.

For example:

• Ĉu la akvotubo iam likis?
• Ĉu iam la akvotubo likis?

Both are possible. The first version is very straightforward and natural. Moving iam can slightly change emphasis, but not the basic meaning.

A rough pronunciation guide:

• Ĉu ≈ choo
• la ≈ lah
• akvotubo ≈ ah-kvo-TOO-bo
• iam ≈ EE-am
• likis ≈ LEE-kis

A few useful pronunciation notes:

• ĉ sounds like ch in church
• u sounds like oo in food
• Stress in Esperanto usually falls on the second-to-last syllable

So:

• akvotúbo
• líkis