1. De It means from, of. The word de in Spanish has several uses.
One of its uses is to show possession. It is used in place of the apostrophe s (‘s) that we have in English.
There is not an apostrophe s in Spanish.

2. Showing possession in English
My mother’s house.
Eric’s book
Maria’s sweater
Olga’s shoes
The examples all use an apostrophe s (‘s) to say who the items belong to.

3. Using de in place of ‘s. My mother’s house Enrique’s book
Maria’s sweater
Olga’s shoes
La casa de mi madre
El libro de Enrique
El suéter de María
Los zapatos de Olga

4. How de works
To show possession in Spanish, use the following construction:
what the person has + de + person
Ejemplo: El libro + de + Susana.  The book of Susana. OR Susana’s book.

5. Vamos a practicar Roberto’s t-shirt Rosario’s grandmother
Manuel’s sister
Estela’s dress
La camiseta de Roberto
La abuela de Rosario
La hermana de Manuel
El vestido de Estela

6. What exactly did we learn today ?
To show possession
How? Using the word de
What is it equivalent to in English?
The apostrophe s (‘s)