It may look strange to those who speak English as a first language, but in Spanish it is very common to use an indirect object pronoun with ser, one of the verbs that usually means "to be."

Such a usage is common when explaining how someone feels about or reacts to something. It can also be used when explaining how one person is going to be or act toward another. When ser is used with an indirect object, they frequently form the equivalent of "to + the indirect object pronoun" or "for + the indirect object pronoun" in English.

Here are a few examples:

• Me es muy difícil bajar de peso. (It is very difficult for me to lose weight.)
• El agua le es medicina. (Water is medicine for him.)
• Las montañas le son bellas. (The mountains are beautiful to her.)
• Voy a serte fiel. (I am going to be faithful to you.)
• El libro nos será muy útil. The book will be very useful for us.
• Todo les será muy fácil. (Everything will be easy for them.)

A number of other verbs can be used with an indirect object in a similar manner to indicate how someone feels or reacts.

• Le suena mal. (It sounds bad to him.)
• Me parece excelente el libro. (The book seems excellent to me.)
• Nos consta que hay un Dios. (It is evident to us that there is a God.)
• Todo le da igual. (It's all the same to her.)