La ŝultro kaj la kubuto estas moveblaj.

In Esperanto, la is the definite article, meaning the.

So:

• la ŝultro = the shoulder
• la kubuto = the elbow

Unlike English, Esperanto has only one article: la. It does not change for singular/plural or gender.

Actually, this sentence does use la twice:

• La ŝultro kaj la kubuto estas moveblaj.

That is very natural, because it clearly marks both nouns as definite: the shoulder and the elbow.

In Esperanto, you can sometimes use one la with coordinated nouns, but repeating it is often clearer and more natural, especially in learner materials.

Kaj means and.

It joins two words or phrases, just like English and:

• la ŝultro kaj la kubuto = the shoulder and the elbow

Its position is the same as in English: it goes between the two things being connected.

In Esperanto, verbs do not change according to the subject.

So whether the subject is singular or plural, you still use estas for the present tense:

• La ŝultro estas movebla. = The shoulder is movable.
• La ŝultro kaj la kubuto estas moveblaj. = The shoulder and the elbow are movable.

This is much simpler than English, where we say is for singular and are for plural.

The ending -j marks the plural.

Here, the subject is plural:

• la ŝultro kaj la kubuto = two things

Because the subject is plural, the adjective describing it must also be plural:

• movebla = movable, mobile
• moveblaj = movable, mobile (plural)

This is called adjective agreement. In Esperanto, adjectives agree with the nouns they describe in number, and sometimes case too.

Because this adjective is:

• plural → needs -j
• not in the accusative → no -n

So the correct form is:

• moveblaj

Here is the pattern:

• movebla = singular
• moveblaj = plural
• moveblan = singular accusative
• moveblajn = plural accusative

In this sentence, moveblaj is a predicate adjective after estas, so it stays in the basic nominative form, just marked for plural.

Moveblaj can be broken down into parts:

• mov- = move
• -ebl- = able to be, possible to
• -a = adjective ending
• -j = plural

So:

• movebla literally means something like able to be moved or movable
• moveblaj = movable / mobile for more than one thing

This kind of word-building is very common in Esperanto.

It depends on context.

Movebla literally means movable or able to move / be moved. In a sentence about body parts like the shoulder and elbow, English often prefers mobile or movable depending on the situation.

So all of these can fit the general idea:

• The shoulder and the elbow are movable.
• The shoulder and the elbow are mobile.

If the meaning has already been given to the learner, the important grammar point is that moveblaj is a plural adjective.

Ŝ is pronounced like English sh.

So:

• ŝultro sounds roughly like SHOOL-tro

A few details:

• ŝ = sh
• u is like oo in food
• Esperanto stress is usually on the second-to-last syllable, so ŜUL-tro

Because each noun refers to one item:

• la ŝultro = the shoulder
• la kubuto = the elbow

When Esperanto lists two singular nouns with kaj, the whole subject becomes plural in meaning. That is why the verb stays estas and the adjective becomes plural:

• La ŝultro kaj la kubuto estas moveblaj.

So the nouns themselves do not need plural endings, because each one is individually singular.

Yes, that may be possible in some contexts, but La ŝultro kaj la kubuto is clearer and more standard for learners.

Using la before both nouns makes it obvious that you mean:

• the shoulder and the elbow

Without the second la, the sentence can still be understood, but repeating it is often better style when naming two specific things.

A singular version would be:

• La ŝultro estas movebla.
• La kubuto estas movebla.

Notice the changes:

• the subject is now one thing
• the adjective becomes singular: movebla instead of moveblaj

The verb stays the same:

• estas in both singular and plural

No. Esperanto nouns do not have grammatical gender in the way many European languages do.

So:

• ŝultro is just shoulder
• kubuto is just elbow

The adjective movebla / moveblaj also does not change for masculine or feminine. It only changes for things like singular/plural and case.