Ho lasciato un promemoria sul telefono per non dimenticare il prelievo di domani.

Ho lasciato is the passato prossimo, a very common Italian past tense.

It is made with:

• ho = present tense of avere
• lasciato = past participle of lasciare

In this sentence, it means something like I left / I’ve left a reminder on the phone.

Italian often uses the passato prossimo where English might use either the simple past (I left) or the present perfect (I’ve left), depending on context.

Because lasciare normally takes avere as its auxiliary in compound tenses.

So:

• ho lasciato = correct
• sono lasciato = not correct here

A simple way to think about it is that lasciare is usually a transitive verb: you leave something. Here, that something is un promemoria.

Good question, because this is one of those words that can surprise learners.

Promemoria is masculine, even though it ends in -a. So you say:

• un promemoria
• il promemoria

Not:

• una promemoria
• la promemoria

Italian has a small number of masculine nouns ending in -a, and promemoria is one of them.

Yes, promemoria often means reminder.

In modern everyday Italian, especially with phones and apps, it can refer to:

• a reminder
• a note to remember something
• a scheduled phone reminder

So in this sentence, ho lasciato un promemoria sul telefono means that the speaker set or left a reminder on their phone.

Sul is a contraction of:

• su
  • il = sul

So literally it is on the phone.

In natural English, though, you might often translate it as:

• on my phone
• in my phone
• on the phone

depending on context.

In Italian, sul telefono is very natural for something entered or stored on a smartphone, like a note, reminder, or calendar item.

Italian often omits possessives when the meaning is obvious from context.

So:

• Ho lasciato un promemoria sul telefono
  naturally suggests on my phone

If the speaker wanted to be extra explicit or contrastive, they could say:

• sul mio telefono = on my phone
• sul tuo telefono = on your phone

But in ordinary speech, leaving out mio is very common.

Per + infinitive is a very common way to express purpose in Italian.

So:

• per dimenticare = in order to forget
• per non dimenticare = in order not to forget

Here it explains why the speaker left the reminder:

• Ho lasciato un promemoria sul telefono per non dimenticare...
• I left a reminder on the phone so as not to forget...

This is one of the most useful Italian patterns to learn:

• per + infinitive = to / in order to
• per non + infinitive = so as not to / in order not to

Because when an infinitive is negated in Italian, non comes directly before the infinitive.

So:

• dimenticare = to forget
• non dimenticare = not to forget

This is different from English word order, but it is completely regular in Italian.

Other examples:

• per non arrivare tardi = so as not to arrive late
• meglio non parlare = better not to speak
• cerco di non sbagliare = I try not to make mistakes

Italian uses definite articles more often than English.

So where English might say:

• I don’t want to forget tomorrow’s blood test / withdrawal / pickup

Italian often prefers:

• non dimenticare il prelievo di domani

The article il makes it sound like a specific, known event: the prelievo scheduled for tomorrow.

This is very natural Italian.

Prelievo can mean different things depending on context, for example:

• a withdrawal (especially money from a bank or ATM)
• a blood draw / blood test sample
• a collection / pickup

In this sentence, the exact meaning depends on the situation. Grammatically, though, it works the same way: it refers to a specific scheduled prelievo, and di domani tells you it is the one happening tomorrow.

Di domani means of tomorrow or more naturally for tomorrow / tomorrow’s.

So:

• il prelievo di domani = tomorrow’s prelievo / the prelievo scheduled for tomorrow

If you said only domani, it would more naturally modify the whole action or the verb, for example:

• Domani lascio un promemoria = Tomorrow I’ll leave a reminder

But here, the idea is not when the reminder is left. It is specifying which prelievo: the one of tomorrow.

Yes. Italian word order is flexible, although the original sentence is very natural.

For example, you could also say:

• Per non dimenticare il prelievo di domani, ho lasciato un promemoria sul telefono.

This puts the purpose first:

• To avoid forgetting tomorrow’s prelievo, I left a reminder on the phone.

You could also hear:

• Ho lasciato sul telefono un promemoria per non dimenticare il prelievo di domani.

That is also correct. The original version is simply a very standard, neutral way to say it.

No. Italian has several natural ways to express the same idea.

For example:

• Ho messo un promemoria sul telefono = I put/set a reminder on the phone
• Ho impostato un promemoria sul telefono = I set a reminder on the phone
• Mi sono segnato il prelievo sul telefono = I made a note of the prelievo on my phone

The original sentence is perfectly fine, but in everyday speech many people might also use mettere or impostare, especially when talking about a smartphone reminder.