La profesorino diris, ke se ni legos paŝo post paŝo, la nova gramatiko fariĝos pli simpla.

Because -ino is the Esperanto suffix for a female person.

• profesoro = a professor / teacher (male or sometimes unspecified, depending on usage)
• profesorino = a female professor / female teacher

So la profesorino means the female teacher/professor.

Diris is the past tense of diri (to say).

• diri = to say
• diras = says / is saying
• diris = said
• diros = will say

So La profesorino diris means The teacher said.

Esperanto tense endings are very regular:

• -as = present
• -is = past
• -os = future

Ke means that and introduces a subordinate clause.

So:

• La profesorino diris = The teacher said
• ke ... = that ...

This is very common in Esperanto:

• Mi pensas, ke... = I think that...
• Li scias, ke... = He knows that...
• Ŝi diris, ke... = She said that...

In English, that is sometimes optional, but in Esperanto ke is normally stated clearly.

Se means if.

It introduces a conditional clause:

• se ni legos paŝo post paŝo = if we read step by step

So the structure is:

• ke se ... , ...
• that if ... , ...

This is completely normal in Esperanto, just as in English.

This is a very common question for English speakers.

In Esperanto, the tense is usually chosen by the actual time meant, not by a special English-style rule for if clauses. So if the reading is in the future, legos is perfectly natural.

• se ni legos = if we will read / if we read in the future

Likewise:

• fariĝos = will become

So the sentence is talking about a future result based on a future action.

English often avoids will after if, but Esperanto does not have to follow that pattern.

Literally, it means step after step.

• paŝo = step
• post = after

So paŝo post paŝo is an idiomatic way to say step by step.

It works much like English expressions built from repetition:

• iom post iom = little by little
• tagon post tago = day after day
• jaron post jaro = year after year

Because this expression is being used adverbially as a fixed phrase meaning step by step, not as a direct object.

In the sentence:

• ni legos paŝo post paŝo

the direct object is not stated. The phrase paŝo post paŝo describes how the reading is done.

Many Esperanto expressions of manner do not need -n. Here it is best learned as a set phrase.

Fariĝos comes from fariĝi, which means to become.

• fari = to make / to do
• fariĝi = to become

So:

• la nova gramatiko fariĝos pli simpla = the new grammar will become simpler

The important part is -iĝ-, which often gives the idea of becoming, getting into a state, or undergoing a change.

Examples:

• ruĝa = red

• ruĝiĝi = to become red

• sidi = to sit
• sidiĝi is not standard, but compare
• starigi = to cause to stand
• stariĝi would suggest becoming standing in older or less usual patterns; more commonly ekstari is used

For your sentence, just remember:

• fari = make
• fariĝi = become

Because simpla is an adjective describing gramatiko.

• gramatiko = grammar
• simpla = simple

In la nova gramatiko fariĝos pli simpla, the word simpla agrees with gramatiko, so it stays an adjective.

Compare:

• Ŝi parolas simple. = She speaks simply.
  Here simple is an adverb.

• La regulo estas simpla. = The rule is simple.
  Here simpla is an adjective.

Since the grammar is/becomes simple, the adjective form is correct.

Because adjectives usually come before the noun in Esperanto, although they can also come after it.

• la nova gramatiko = the new grammar
• la gramatiko nova = also possible, but less neutral in many contexts

The usual, straightforward order is:

• article + adjective + noun

So la nova gramatiko is the most natural basic order.

La is the definite article, meaning the.

• la profesorino = the teacher
• la nova gramatiko = the new grammar

It is used when the speaker has a specific person or thing in mind.

In this sentence, both are treated as identifiable:

• a particular teacher
• a particular new grammar

Unlike English, Esperanto has only one definite article: la. It does not change for gender, number, or case, except that nouns themselves can change.

Esperanto punctuation often marks subordinate clauses clearly.

In this sentence:

• La profesorino diris, ke ...
• ..., ke se ni legos paŝo post paŝo, la nova gramatiko fariĝos pli simpla.

The commas help separate the main clause from the subordinate clause, and the if clause from the rest of that clause.

This is very common and helps readability. Esperanto punctuation is often a bit more explicit than English punctuation.

The sentence can be broken down like this:

1. La profesorino diris
   = The teacher said

2. ke ...
   = that ...

3. se ni legos paŝo post paŝo
   = if we read step by step

4. la nova gramatiko fariĝos pli simpla
   = the new grammar will become simpler

So the full structure is:

• main clause: La profesorino diris
• content clause introduced by ke
• inside that, a conditional clause introduced by se
• then the main result clause

This kind of nesting is very normal in Esperanto.

Not literally. Legos is definitely future tense:

• legi = to read
• legas = read / are reading
• legis = read / were reading
• legos = will read

However, when translating the whole sentence into natural English, English may use present tense after if:

• if we read step by step

Even so, the Esperanto form is still future. So grammatically, legos means will read, even if the best English translation may sound different.

Yes.

The subject is la nova gramatiko.

• la nova gramatiko = subject
• fariĝos = will become
• pli simpla = predicative adjective describing the subject

So the sentence says that the new grammar will enter a new state: it will become more simple / simpler.

That is why simpla matches gramatiko as an adjective.

Yes, but the meaning would be a little different.

• estos pli simpla = will be simpler
• fariĝos pli simpla = will become simpler

Estos describes a state. Fariĝos emphasizes a change into that state.

In this sentence, fariĝos suggests that, as a result of reading step by step, the grammar will seem or become easier/simpler to us over time. That idea of change makes fariĝos a good choice.