Me alegra que ya hayas puesto la foto sobre el estante.

Because alegrar is being used in an impersonal-style structure: something pleases/gladdens someone. The subject is not I; the subject is the whole que clause:

Que ya hayas puesto la foto sobre el estante = the thing that makes me happy.

So Spanish says me alegra = it makes me happy, not I glad. If you wanted a more direct I am happy, Spanish often uses me alegro instead, but that usually goes with de: Me alegro de que...

After expressions of emotion such as me alegra que, Spanish normally uses the subjunctive in the following clause. The speaker is reacting emotionally to a situation, and that triggers the subjunctive.

So:

• Me alegra que ya hayas puesto... = correct
• Me alegra que ya has puesto... = not correct

This is one of the most common subjunctive patterns in Spanish.

Because two things are happening at once:

1. The clause needs the subjunctive after me alegra que.
2. The action of putting the photo up is viewed as already completed relative to the present.

That is why Spanish uses the present perfect subjunctive:

• hayas puesto = you have put / you’ve put

Compare:

• has puesto = present perfect indicative
• hayas puesto = present perfect subjunctive

So the sentence is not just about past time; it is about a completed action inside a subjunctive clause.

Because poner has an irregular past participle: puesto. This is one you simply need to learn.

Some common irregular past participles are:

• poner → puesto
• hacer → hecho
• ver → visto
• decir → dicho
• escribir → escrito

So hayas puesto is the correct form.

Spanish often leaves out subject pronouns because the verb form already shows who the subject is. Hayas puesto tells you the subject is tú.

So:

• que ya hayas puesto la foto...
• que tú ya hayas puesto la foto...

Both are possible, but the version without tú is more normal unless you want emphasis or contrast.

Ya means already. It shows that the action has been completed by now.

So ya hayas puesto means you have already put. Without ya, the sentence would still work, but it would lose that sense of this is done now / this has finally happened.

Yes, Spanish allows some flexibility. For example, these are possible:

• Me alegra que ya hayas puesto la foto...
• Me alegra que hayas ya puesto la foto...

But the first one, with ya before the verb phrase, is more natural and common in everyday Spanish.

It is grammatical, but the most natural choice depends on the exact meaning.

• sobre el estante often suggests on / on top of the shelf
• en el estante often means on the shelf or in the shelf space
• encima del estante more clearly means on top of the shelf

So if the photo is resting on the shelf itself, many speakers might prefer en el estante. If you really mean on top of the shelf unit, encima del estante may be clearer.

Yes. That is also natural and very common.

There is a slight structural difference:

• Me alegra que... = It makes me happy that...
• Me alegro de que... = I’m glad that...

In practice, both can work in many situations. Learners often meet both patterns, so it is useful to recognize them.

A helpful breakdown is:

• Me alegra = It makes me happy
• que = that
• ya hayas puesto = you have already put
• la foto = the photo
• sobre el estante = on / over the shelf

So the grammar pattern is:

[indirect object pronoun] + alegrar + que + subjunctive clause

A very common model to remember is:

• Me alegra que vengas.
• Me alegra que hayas venido.
• Me alegra que ya hayas puesto la foto sobre el estante.