Ĉi tiu profesio estas interesa.

Tiu means that one / that in the basic correlative system, and ĉi is a little particle that brings it closer. So:

• tiu = that
• ĉi tiu = this

Esperanto often uses ĉi tiu for this and tiu for that.

You may also see the order tiu ĉi. It means the same thing as ĉi tiu.

Examples:

• ĉi tiu libro = this book
• tiu libro = that book

In Esperanto, nouns normally end in -o. So profesio is a noun.

Some common noun endings:

• libro = book
• domo = house
• profesio = profession

This is one of the most regular parts of Esperanto grammar: if you see -o, you can usually expect a noun.

Because interesa is an adjective, and adjectives in Esperanto normally end in -a.

So:

• interesa = interesting
• bona = good
• granda = big

In this sentence, interesa describes profesio, so it has the adjective ending -a.

Estas is the present tense of esti, meaning to be. So estas interesa means is interesting.

The sentence structure is:

• Ĉi tiu profesio = this profession
• estas = is
• interesa = interesting

So the full sentence is literally: This profession is interesting.

Esperanto usually keeps the verb to be where English does.

Actually, it already does match. In Esperanto, adjectives agree with nouns in number and case.

Here both words are singular and in the basic form:

• profesio
• interesa

If the noun were plural, the adjective would also become plural:

• Ĉi tiuj profesioj estas interesaj. = These professions are interesting.

So in your sentence, interesa is the correct agreeing form for singular profesio.

Esperanto does have an article, la, meaning the, but it is used only when needed.

Here, ĉi tiu already makes the noun definite:

• ĉi tiu profesio = this profession

Because this already points to a specific profession, you do not need la.

You would not normally say:

• la ĉi tiu profesio

That would be unnecessary and incorrect in normal Esperanto.

Yes, but it would mean something different.

• Ĉi tiu profesio estas interesa. = This profession is interesting.
• Tiu profesio estas interesa. = That profession is interesting.

So both are correct, but ĉi tiu refers to something near the speaker, while tiu refers to something farther away or less immediate.

A simple pronunciation guide:

• ĉi ≈ chee
• tiu ≈ TEE-oo
• profesio ≈ pro-fe-SEE-o
• estas ≈ ES-tas
• interesa ≈ in-te-RE-sa

A few helpful points:

• ĉ sounds like ch in church
• each vowel is pronounced clearly
• stress is usually on the second-to-last syllable

So:

• pro-fe-SI-o? No — actually pro-fe-SI-o would be wrong if syllabified that way; the correct stress is pro-fe-SI-o only if the syllables are counted as pro-fe-si-o, where si is second-to-last.
• interesa has stress on re: in-te-RE-sa

This is the most normal word order:

subject + verb + adjective/complement

• Ĉi tiu profesio = subject
• estas = verb
• interesa = complement

Esperanto word order is fairly flexible, so other orders are possible for emphasis, but this one is the standard, neutral order and the best one for learners to use first.

Not exactly. Profesio usually means profession, so it often suggests a field, occupation, or trained line of work rather than one specific job position.

For example:

• profesio = profession
• laboro = work
• posteno = post/position/job role

So if the translation shown to you is This profession is interesting, then profesio is a good fit.

The base is interes-, which relates to interest.

From that root you can build:

• interesa = interesting
• intereso = interest
• interesi = to interest
• interesite or other derived forms in context

This is very typical Esperanto word-building: a stable root plus regular endings.

Not quite.

• Ĉi tiu profesio estas interesa. = This profession is interesting.
• Ĉi tio estas interesa. = This is interesting.

Ĉi tio means this by itself, without naming the noun.
Ĉi tiu profesio means this profession, where the noun is stated explicitly.

So they are related, but not the same sentence.