Estoy afónico hoy.

Because estar is used for a temporary state or condition, and having no voice / being hoarse is usually temporary.

• Estoy afónico hoy = I’m hoarse / I’ve lost my voice today.
• Soy would suggest a more permanent characteristic, which does not fit here.

So this is a classic estar + adjective structure for a temporary physical condition.

Afónico means hoarse, without a voice, or having lost one’s voice.

It comes from afonía, which means loss of voice. In everyday use, estar afónico often means your voice is weak, rough, or almost gone.

Depending on context, English might translate it as:

• I’m hoarse
• I’ve lost my voice
• My voice is gone

Spanish often leaves out subject pronouns because the verb already shows who the subject is.

• Estoy already means I am
• So yo is not necessary

You could say Yo estoy afónico hoy, but it usually sounds more emphatic, as if you are stressing I.

The most natural neutral version is simply:

• Estoy afónico hoy

Yes. It is an adjective, so it changes to agree with the person in gender and number.

Forms:

• afónico = masculine singular
• afónica = feminine singular
• afónicos = masculine or mixed plural
• afónicas = feminine plural

Examples:

• A man: Estoy afónico
• A woman: Estoy afónica
• A group of men / mixed group: Estamos afónicos
• A group of women: Estamos afónicas

Yes, hoy can move around. Spanish word order is fairly flexible.

These are all possible:

• Estoy afónico hoy
• Hoy estoy afónico
• Estoy hoy afónico — possible, but less natural in many contexts

The most natural choices are usually:

• Estoy afónico hoy
• Hoy estoy afónico

Putting hoy at the end is very natural and often sounds like a simple statement of how you are today.

It is pronounced roughly like ah-FO-nee-ko.

Important points:

• The stress falls on fó
• The written accent in afónico shows the stressed syllable

So:

• a-FÓ-ni-co

In standard Spain Spanish, the c before o sounds like a regular k, so -co is pronounced ko.

Not exactly.

• afónico usually suggests that your voice is gone or nearly gone
• ronco usually means hoarse in the sense of sounding rough or raspy

So there is overlap, but they are not always identical.

For example:

• Estoy afónico = I’ve basically lost my voice / my voice is very weak
• Estoy ronco = My voice sounds rough or husky

In real life, both may be used depending on the degree and the speaker.

Yes, you can.

• Estoy afónico = I’m hoarse / I’ve lost my voice
• Tengo afonía = I have loss of voice / I have aphonia

But estoy afónico is usually more everyday and conversational.
Tengo afonía sounds a bit more formal or medical.

In normal conversation, a Spanish speaker would very often say:

• Estoy afónico

Yes, it is completely natural in Spain.

A speaker in Spain would understand it immediately, and it sounds normal and idiomatic. It is also understandable in other Spanish-speaking countries, though some regions may more often prefer expressions like:

• Estoy ronco
• Me quedé sin voz = I lost my voice

Still, Estoy afónico hoy is perfectly correct and natural Spanish.

Yes.

• Estoy afónico = I’m hoarse / I’ve lost my voice
• Estoy afónico hoy = I’m hoarse today

Adding hoy just makes the time reference explicit. Without it, the meaning is still clear from context.

It follows a very common pattern:

• estar + adjective + time expression

Breakdown:

• Estoy = I am
• afónico = hoarse / without a voice
• hoy = today

This pattern is used a lot for temporary states:

• Estoy cansado hoy = I’m tired today
• Estoy enfermo hoy = I’m sick today
• Estoy ocupado hoy = I’m busy today

So Estoy afónico hoy is a very useful model sentence.