Está alegre hoy.

Spanish often uses estar for a temporary state or condition, and ser for something more permanent or defining.

So Está alegre hoy suggests that the person is cheerful today, as a current mood or temporary state.

• Está alegre hoy = cheerful today / in a cheerful mood today
• Es alegre = he/she is a cheerful person by nature

That is one of the most important contrasts between ser and estar.

Está is the third-person singular form of estar in the present tense.

It can mean:

• he is
• she is
• it is
• you are (formal singular, usted)

So the full sentence could be understood as:

• Él está alegre hoy
• Ella está alegre hoy
• Usted está alegre hoy

Spanish often leaves the subject unstated if it is clear from context.

Spanish is a pro-drop language, which means subject pronouns are often omitted because the verb ending already gives information about the subject.

In Está alegre hoy, the verb está tells you it is third-person singular or usted.

You would add the pronoun only if needed for:

• emphasis
• contrast
• clarity

For example:

• Él está alegre hoy, pero ella no.
• Ella está alegre hoy.

Without the pronoun, the sentence sounds very natural.

No. Alegre is an adjective that has the same form for masculine and feminine singular.

So you can say:

• Él está alegre
• Ella está alegre

For the plural, it does change:

• Ellos están alegres
• Ellas están alegres

So the only change here is usually singular vs. plural, not masculine vs. feminine.

Here, alegre is an adjective. It describes the subject’s emotional state.

The structure is:

• está = verb
• alegre = adjective
• hoy = adverb of time

So this is a very common Spanish pattern:

estar + adjective

Examples:

• Está cansado.
• Está triste.
• Está nerviosa.

In your sentence, alegre describes how someone feels.

Yes, hoy can go in different places, although the most neutral and natural version here is Está alegre hoy or Hoy está alegre.

Common possibilities:

• Está alegre hoy.
• Hoy está alegre.

Both are correct.

Putting hoy first often gives it a little more emphasis, as in today, specifically.

A less common order like Está hoy alegre is possible, but it sounds more marked or literary and is not the most neutral everyday choice.

Yes, very important.

• está with an accent = is
• esta without an accent = this (feminine singular)

Examples:

• Está alegre hoy. = is cheerful today
• Esta chica... = this girl...

So the written accent changes the meaning completely.

Yes, if the speaker is using usted, the formal singular you.

Because está can refer to:

• he
• she
• it
• usted

So depending on context, Está alegre hoy could mean:

• He is cheerful today
• She is cheerful today
• You are cheerful today (formal)

In everyday conversation, context usually makes it clear.

It is similar, but not always exactly the same.

• alegre = cheerful, happy, lively
• contento/contenta = pleased, happy, glad, satisfied

In many situations they overlap, but alegre can sound a bit more like a visible cheerful mood, while contento/contenta can suggest being pleased or satisfied.

Also notice the agreement:

• Él está contento
• Ella está contenta

Unlike alegre, contento/contenta changes for gender.

Normally, no. With hoy, Spanish strongly prefers está because the sentence is talking about a mood or temporary condition today.

• Está alegre hoy = natural
• Es alegre hoy = sounds wrong or very unnatural in normal usage

If you want to describe someone’s general personality, then ser is correct:

• Es alegre. = He/She is a cheerful person.

So hoy is a big clue that estar is the right choice.

The sentence follows this pattern:

[verb] + [adjective] + [time expression]

More specifically:

• Está = present tense of estar
• alegre = adjective
• hoy = adverb of time

So it is a very useful pattern you can reuse:

• Está triste hoy.
• Está ocupado hoy.
• Está mejor hoy.

This is one of the most common ways to describe how someone is feeling or doing at a particular moment.