En caso de que el gráfico no esté claro, la profesora añade otro ejemplo en la pizarra.

Both can express a condition, but they are not exactly the same.

• si = if
• en caso de que = in case

So:

• Si el gráfico no está claro... = If the graph isn’t clear...
• En caso de que el gráfico no esté claro... = In case the graph isn’t clear...

En caso de que sounds a bit more formal and more like preparing for a possible situation. It is also followed by the subjunctive, which is why you get esté.

Because en caso de que triggers the subjunctive.

The speaker is talking about a possible or hypothetical situation, not stating a fact. In Spanish, that often requires the subjunctive.

• está = present indicative
• esté = present subjunctive

So:

• el gráfico no está claro = the graph is not clear
• en caso de que el gráfico no esté claro = in case the graph may not be clear

This is one of the most common patterns to learn:

• en caso de que + subjunctive

Esté is the yo / él / ella / usted form of the present subjunctive of estar.

Present subjunctive of estar:

• yo esté
• tú estés
• él/ella/usted esté
• nosotros estemos
• vosotros estéis
• ellos/ellas/ustedes estén

In this sentence, the subject is el gráfico, which is singular, so Spanish uses the él/ella/usted form: esté.

In this context, estar claro means to be clear / understandable at that moment or in that situation.

• estar claro = to be clear, obvious, understandable
• ser claro often describes something as having a generally clear nature or style

Here the sentence is about whether the graph is clear to the students in that specific case, so estar is the natural choice.

Examples:

• La explicación no está clara. = The explanation isn’t clear.
• Este profesor es claro al hablar. = This teacher is clear when speaking.

Here el gráfico most naturally means the graph, chart, or diagram, depending on context.

In classroom or academic Spanish, gráfico is often used for visual data or a visual representation.

Possible translations:

• graph
• chart
• diagram

The best English word depends on what is being shown.

Because the sentence begins with a subordinate clause:

• En caso de que el gráfico no esté claro = dependent clause
• la profesora añade otro ejemplo en la pizarra = main clause

In Spanish, when this kind of clause comes first, it is normally separated from the main clause by a comma.

It works much like English:

• If the graph isn’t clear, the teacher adds another example on the board.

Because the sentence describes a present or habitual action:

• la profesora añade = the teacher adds

It sounds like something she does whenever that situation happens, not a one-time action in the past.

So the structure is:

• possible condition: en caso de que...
• regular response: la profesora añade...

If it were past, you might see:

• la profesora añadió = the teacher added

The accent mark in añade is part of the normal spelling of the verb añadir.

The ñ is a separate letter in Spanish, different from n:

• ano and año are completely different words
• anade would be wrong
• añade is correct

The verb is:

• infinitive: añadir
• él/ella/usted present: añade

So the important spelling point here is really the ñ, not an extra written stress accent like in words such as gráfico.

In Spanish, otro already includes the idea of another, so you do not use un before it.

• otro ejemplo = another example
• un otro ejemplo = incorrect

This is a very common rule:

• Quiero otro café. = I want another coffee.
• Necesitamos otra silla. = We need another chair.

Because otro is a determiner/adjective that normally goes before the noun in Spanish.

So:

• otro ejemplo = another example
• otra profesora = another teacher

This is the standard position. English speakers sometimes want to place adjectives after the noun because many Spanish adjectives do that, but otro usually comes before it.

En la pizarra usually means on the board.

Even though en often means in, it can also mean on, depending on context.

Here:

• añadir otro ejemplo en la pizarra = add another example on the board

In Spain, pizarra is the usual word for a classroom board, including a whiteboard in many contexts.

Spanish often uses the definite article more than English does.

• la profesora = the teacher

This usually refers to a specific teacher already known from context. In English, we also often say the teacher, so this part matches quite well.

Without the article, profesora would usually sound incomplete here.

Yes, it is grammatically possible, but it changes the nuance a bit.

• no esté claro sounds more natural for not being clear / understandable in that situation
• no sea claro can sound more like not being clear by nature or in its wording/design

In everyday classroom Spanish, estar claro is the more idiomatic choice for this meaning.

So the original sentence is the most natural one.

Most naturally, it sounds like a general habit or a typical classroom action.

• En caso de que... = if that situation happens
• la profesora añade... = the teacher adds...

So it feels like:

• Whenever the graph isn’t clear, the teacher adds another example on the board.

If you wanted a single future event, Spanish would often make that clearer with context or a different main verb form.

Yes, but the original order is very natural.

Original:

• En caso de que el gráfico no esté claro, la profesora añade otro ejemplo en la pizarra.

You could also say:

• La profesora añade otro ejemplo en la pizarra en caso de que el gráfico no esté claro.

That is still correct, but the original version is often better because it puts the condition first, which helps the listener understand the sentence structure right away.

More or less, yes. The full expression is:

• en caso de que

You should learn it as a fixed chunk, just like:

• antes de que
• después de que
• a fin de que

Many Spanish expressions include de que, and the best approach is often to memorize the whole phrase rather than trying to translate each word separately every time.