Tiu movo estis tre bona.

Tiu is a demonstrative word: it points to a specific thing, like that in English.

In tiu movo, it works like an adjective modifying movo. So it means that move.

A few useful related forms:

• tiu movo = that move
• tiuj movoj = those moves
• tiun movon = that move (as a direct object)

You can also use tiu by itself, without a noun, if the noun is understood.

In Esperanto, nouns end in -o.

So:

• mov- = the root idea of moving
• movo = a move, a movement

This is one of the most basic Esperanto patterns:

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

So from the same root, you can get forms like:

• movi = to move
• movo = a move
• mova = moving, movable-related depending on context
• move = in a moving way

Estis is the past tense of esti, which means to be.

So:

• estas = is / are / am
• estis = was / were
• estos = will be

Esperanto verbs do not change based on the subject. That means:

• mi estis
• vi estis
• li estis
• ili estis

all use the same verb form estis for the past tense.

Because bona describes the noun movo.

• bona = good, as an adjective
• bone = well, as an adverb

In this sentence, the structure is:

• Tiu movo = the subject
• estis = was
• tre bona = very good

After esti, Esperanto normally uses an adjective to describe the subject:

• La libro estas interesa.
• La vetero estis malbona.
• Tiu movo estis tre bona.

Using bone here would sound wrong, because bone describes how something is done, not what something is like.

Because adjectives in Esperanto always end in -a.

So bona is the adjective good.

It also agrees with the noun it describes. Since movo is singular and has no -n, the adjective is also singular and has no -n:

• bona movo = a good move
• bonaj movoj = good moves
• bonan movon = a good move (direct object)
• bonajn movojn = good moves (direct object)

Even though bona comes after estis, it still refers to movo, so it stays in agreement with it.

Tre means very.

It is an adverb, and here it modifies the adjective bona:

• bona = good
• tre bona = very good

In Esperanto, tre usually comes directly before the word it strengthens:

• tre bona = very good
• tre rapide = very quickly
• tre interesa = very interesting

Because there is no direct object in this sentence.

The noun movo is the subject, not the object. The sentence is simply describing that subject:

• Tiu movo = subject
• estis = linking verb
• tre bona = description of the subject

The accusative -n is mainly used for direct objects and some other functions such as direction.

Compare:

• Tiu movo estis tre bona. = no direct object
• Mi vidis tiun movon. = tiun movon has -n because it is the object of vidis

Also, after esti, the descriptive adjective does not take -n unless grammar specifically requires it for agreement with an accusative noun in another structure.

Because tiu already makes the noun definite and specific.

In Esperanto, you normally do not combine la with tiu:

• tiu movo = that move
• not la tiu movo

Both la and tiu help identify something, but tiu is already enough by itself.

So tiu movo is the natural form.

The given order is the most neutral and natural:

• Tiu movo estis tre bona.

Esperanto word order is fairly flexible, because endings show grammatical roles clearly. So other orders can be possible for emphasis, for example:

• Tre bona estis tiu movo.

That puts more focus on tre bona.

Still, for learners, subject + verb + complement is the safest and most standard order.

This is a very common question.

• tiu = that
• ĉi tiu = this

So:

• Tiu movo estis tre bona. = That move was very good.
• Ĉi tiu movo estas tre bona. = This move is very good.

The little word ĉi brings the idea closer to the speaker. You will often see it before or after the demonstrative:

• ĉi tiu movo
• tiu ĉi movo

Both mean this move. The first is more common.