Miaj gefratoj ne ĉiam ludas kune, sed ni ĉiuj ankoraŭ helpas unu la alian.

Because gefratoj is plural, and Esperanto adjectives/possessive words agree with the noun in number and case.

• mia gefrato = my sibling
• miaj gefratoj = my siblings

The -j shows plural on both the noun and the modifier.

Gefratoj means siblings or literally brothers and sisters.

It is built from:

• frato = brother
• fratoj = brothers
• gefratoj = brothers and sisters together / siblings

The prefix ge- is used for a mixed group of males and females, especially in family words.

The prefix ge- shows that the group includes both sexes together.

So:

• fratoj = brothers
• fratinoj = sisters
• gefratoj = brothers and sisters together

A native English speaker often learns gefratoj as the normal way to say siblings.

Because ne ĉiam means not always, which is the idea here.

• ne ĉiam ludas kune = they do not always play together

If you said ĉiam ne, that would mean something closer to always not, which is a different idea and usually much stronger or less natural here.

So:

• ne ĉiam = not always
• ĉiam ne = always not

Because -as is the present-tense ending in Esperanto.

• ludas = play / are playing
• helpas = help / are helping

Esperanto verbs do not change based on person or number. The same form is used with all subjects:

• mi ludas
• vi ludas
• li ludas
• ni ludas

So ludas and helpas are just present tense.

Kune means together.

The ending -e marks an adverb in Esperanto. Adverbs describe verbs, adjectives, or whole situations.

Here kune describes ludas:

• ludas kune = play together

So the sentence is saying they do not always play together.

Because the focus changes.

• miaj gefratoj talks about my siblings
• ni ĉiuj means all of us

So the first clause is about what the siblings do:

• they do not always play together

The second clause includes the speaker too:

• we all still help one another

This is natural in Esperanto and in English.

Ĉiuj means all.

So ni ĉiuj means we all or all of us.

It emphasizes that the whole group is included. In this sentence, it means that everyone in the group still helps each other, even if they do not always play together.

Here ankoraŭ means still.

It shows that something continues to be true:

• they do not always play together,
• but they still help one another.

In other contexts, ankoraŭ can sometimes be translated as yet, but still is the best fit here.

Unu la alian is the standard Esperanto expression for one another or each other.

It is used when the action goes back and forth between members of a group.

So:

• ni helpas unu la alian = we help one another / we help each other

It is a reciprocal expression: each person helps the others.

Because in the expression unu la alian, the case ending is placed on alia.

Here helpi takes a direct object, so the reciprocal expression appears in the accusative:

• unu la alian

The -n goes on alian because that part carries the grammatical case in this set expression.

Also:

• la never takes endings
• unu stays as unu in this fixed pattern

So learners usually just memorize:

• unu la alia = one another
• unu la alian = one another (as a direct object)

Because possessive words like mia, via, lia, nia, etc. usually already make the noun definite.

So Esperanto normally says:

• miaj gefratoj = my siblings

not:

• la miaj gefratoj

This works much like English, where we say my siblings, not the my siblings.