Understanding Italian grammar can be tricky, especially when it comes to using the passive voice. One important part of this is how adjectives change when we use passive sentences. Knowing this will help you become better at writing and speaking in Italian.

In Italian, we create a passive voice by using the helping verb "essere" (to be) along with the past participle of the main verb. The fun part is that the past participle and the subject of the sentence need to match in gender and number.

For example, in the sentence "Il libro è stato letto" (The book has been read), "letto" is the past participle of "leggere" (to read). Since "libro" (book) is masculine and singular, "letto" stays masculine and singular too. But if we change the subject to a feminine word, like "la lettera" (the letter), the sentence becomes "La lettera è stata letta." Here, "letto" changes to "letta" to match "lettera."

Now, let’s look at how adjectives fit into these sentences. If we want to say how something is done in a passive sentence, we might say "Il libro è stato scritto bene" (The book was written well). The word "bene" stays the same because it doesn’t change with gender. But if we used "buono" (good), it wouldn’t work like this: "Il libro è stato scritto buono" is not correct.

Also, adjectives need to change based on the subject in passive sentences. For example, in "La casa è stata costruita alta" (The house was built tall), "alta" changes to agree with "casa."

To really get it, try making your own passive sentences with different subjects and adjectives.

Here are a couple of examples:

1. "Le stanze sono state decorate colorate." (The rooms have been decorated colorful.)
2. "I film sono stati visti interessanti." (The films have been seen interesting.)

Always remember to match the adjectives with the gender and number of the subject in passive voice. Getting this right will help you get much better at Italian!