Tiu rajto estas grava por ĉiu volontulo.

Tiu means that. Ĉi tiu means this.

So Tiu rajto is that right, while Ĉi tiu rajto would be this right. Esperanto makes a clear distinction here:

• tiu = that
• ĉi tiu = this

You can also place ĉi after the word: tiu ĉi rajto, though ĉi tiu rajto is more common.

Because tiu already makes the noun definite.

In Esperanto, you normally do not use la together with demonstratives like:

• tiu = that
• ĉi tiu = this

So you say:

• tiu rajto
• ĉi tiu rajto

not:

• la tiu rajto

The demonstrative already does the job that the would do in English.

The ending -o marks a noun in Esperanto.

So:

• rajto = a right
• volontulo = a volunteer

This is one of the most useful basic patterns in Esperanto:

• -o = noun
• -a = adjective
• -e = adverb
• -i = infinitive verb

That means you can immediately recognize rajto and volontulo as nouns.

Because grava is an adjective, and here it describes tiu rajto.

In this sentence, estas grava means is important. Esperanto uses an adjective after esti just like English does:

• La libro estas interesa. = The book is interesting.
• Tiu rajto estas grava. = That right is important.

If you used grave, that would be an adverb, meaning importantly or in an important way, which would not fit here.

So:

• grava = important, as an adjective
• grave = importantly, as an adverb

Because it is not a direct object here.

The sentence structure is:

• Tiu rajto = subject
• estas = verb
• grava = predicate adjective
• por ĉiu volontulo = prepositional phrase

The -n ending is mainly used for direct objects and for some expressions of direction. But after esti, the describing adjective does not take -n.

So this is correct:

• Tiu rajto estas grava.

not:

• Tiu rajto estas gravan.

Estas is the present-tense form of esti, which means to be.

So:

• esti = to be
• estas = is / am / are

Esperanto uses the same present-tense form for all persons:

• mi estas = I am
• vi estas = you are
• li estas = he is
• ili estas = they are

So Tiu rajto estas grava literally follows a very regular pattern: subject + estas + adjective.

Por usually means for in the sense of for the benefit of, for, or intended for.

Here, grava por ĉiu volontulo means important for every volunteer.

That is the natural choice in Esperanto for this idea. Compare:

• utila por infanoj = useful for children
• facila por mi = easy for me
• grava por ĉiu volontulo = important for every volunteer

A different preposition, such as al, would usually express a different relationship.

It can correspond to both every volunteer and each volunteer, depending on context.

• ĉiu = each / every
• volontulo = volunteer

So por ĉiu volontulo means for each volunteer or for every volunteer.

Esperanto ĉiu focuses on individuals one by one, even when the English translation might simply use every.

Both are possible, but they are slightly different.

• ĉiu volontulo = each/every volunteer
• ĉiuj volontuloj = all volunteers

In many contexts, the difference is small, but ĉiu volontulo emphasizes individuals one at a time, while ĉiuj volontuloj refers to the whole group.

So this sentence highlights that the right matters to every individual volunteer.

Because it comes after the preposition por.

Normally, nouns after prepositions do not take -n, unless there is a special directional use with certain prepositions. Here there is no motion or direction; it is simply:

• por ĉiu volontulo = for every volunteer

So no accusative ending is needed.

Yes. In Esperanto, adjectives agree with the nouns they describe in number and case.

Here:

• rajto is singular
• it is not accusative
• so the adjective is also singular and without -n

That gives:

• grava

If the noun were plural, you would use gravaj:

• Tiuj rajtoj estas gravaj. = Those rights are important.

If there were accusative as well, the adjective would match that too.

Yes, Esperanto word order is fairly flexible, but the neutral order here is very natural:

• Tiu rajto estas grava por ĉiu volontulo.

You could move parts around for emphasis, for example:

• Por ĉiu volontulo tiu rajto estas grava.

That puts more emphasis on for every volunteer. But for learners, the original order is the clearest and most standard.

It has a very common Esperanto pattern:

subject + esti + adjective + prepositional phrase

Breaking it down:

• Tiu rajto = subject
• estas = is
• grava = important
• por ĉiu volontulo = for every volunteer

This is a useful model for making many similar sentences, such as:

• Tiu libro estas interesa por studentoj.
• La regulo estas klara por ĉiuj.
• La helpo estas grava por la teamo.