Ĉu vi scias la horon?

Ĉu is the standard Esperanto word used to turn a statement into a yes/no question.

• Vi scias la horon. = You know the time.
• Ĉu vi scias la horon? = Do you know the time?

Unlike English, Esperanto does not usually need a helping verb like do for this kind of question. You simply add ĉu at the beginning.

Esperanto does not use an extra auxiliary verb like English do to form ordinary yes/no questions.

English:

• You know the time.
• Do you know the time?

Esperanto:

• Vi scias la horon.
• Ĉu vi scias la horon?

So ĉu does the job that English often does with word order and do.

Vi can mean:

• you singular
• you plural
• formal you
• informal you

Esperanto normally uses the same pronoun for all of these. So Ĉu vi scias la horon? can be said to one person or to more than one person.

There is an older/intimate singular form, ci, but it is very rare in normal modern Esperanto.

This is a very common learner question. In Esperanto:

• scii = to know a fact, piece of information, answer, skill, etc.
• koni = to know a person, place, or thing by acquaintance/familiarity

So:

• Mi scias la respondon. = I know the answer.
• Mi konas lin. = I know him.

In Ĉu vi scias la horon?, you are asking whether someone knows a piece of information, so scii is the correct verb.

The -n marks the direct object in Esperanto.

Here:

• vi = the subject
• scias = the verb
• la horon = the thing known, so it is the direct object

That is why horo becomes horon.

Without the -n, the sentence would be grammatically wrong in standard Esperanto.

Yes, horo literally means hour, but in this expression la horo or la horon can mean the time in the sense of what time it is.

So this sentence is idiomatic Esperanto for asking whether someone knows the current time.

A more explicit version is:

• Ĉu vi scias, kioma horo estas?
  = Do you know what time it is?

But Ĉu vi scias la horon? is also normal and understandable.

La is the definite article, meaning the.

In this sentence, la horon refers to a specific thing: the current time. So Esperanto uses la, just as English says the time.

You would not normally say Ĉu vi scias horon? for this meaning.

A simple pronunciation guide is:

CHOO vee STSEE-as la HO-ron

A few details:

• ĉ sounds like ch in church
• sc before i sounds like sts or stsee
• stress in Esperanto is always on the second-to-last syllable

So:

• Ĉu → one syllable
• vi → one syllable
• sci-as → stress on sci
• ho-ron → stress on ho

Yes, it is natural, especially if you are asking whether someone is able to tell you the time.

Other common ways include:

• Kioma horo estas? = What time is it?
• Ĉu vi scias, kioma horo estas? = Do you know what time it is?

So Ĉu vi scias la horon? is fine, but if you want the most direct equivalent of What time is it?, then Kioma horo estas? is often used.

Yes, Esperanto word order is fairly flexible, but not all orders are equally natural.

The normal order here is:

• Ĉu vi scias la horon?

Because -n marks the object, you could in theory move things around, but this standard order is the clearest and most natural for learners.

For example, La horon ĉu vi scias? is possible for emphasis, but it is not the neutral everyday form.

So the best version to learn first is:

• Ĉu vi scias la horon?