You don't always have to use an adjective such as feliz or alegre to refer to someone being happy or becoming happy. Various verbs can be used for that purpose as well.
Alegrar is the most common verb of happiness. It can be used simply to mean "to make happy," or in the reflexive form of alegrarse it can be used for "to be happy" or "to become happy." Of course, in translation you can use other English words such as "joyful," "cheerful" or "pleased," depending on the context.
- Me alegro de haberlo comprado. I am pleased with having bought it.
- Creía que te alegrarías de verme. I thought you would be happy to see me.
- Es algo que te alegrará la tarde. It's something to make your afternoon happy. (Literally, it is something that will make the afternoon happy for you.)
- Lo único que le alegraba los lunes era el hecho que era el día de ir a comprar provisiones de chocolate para toda la semana. The only thing that cheered him up on Mondays was the fact that it was the day of going shopping for the week's chocolate supply.
- No me alegra la muerte de un ser humano. The death of a human being doesn't make me happy.
Contentar, obviously a cognate of the word "content," can be used in much the same way. It often carries the idea of satisfaction.
- Cuando te veo me contento. When I see you I'm content.
- Los administradores se contentaban con dedicar a sus clientes una mínima cantidad de tiempo. The administrators were content to devote a minimum amount of time to their clients.
- No nos contentemos con lo que tenemos. Let's not be satisfied with what we have.
- No sería extraño para nadie que los resultados contenten a Chávez. It wouldn't seem strange to anyone for Chávez to be happy with the outcome.
Deleitar, a cognate of "to delight," typically has that meaning:
- Ella me deleitó con su artículo sobre nuestros miedos. She delighted me with her article about our fears.
- En primavera te deleito, en verano te refresco, en otoño te alimento, y en invierno te caliento. ¿Qué soy? (Un árbol.) In spring I delight you, in summer I refresh you, in fall I feed you and in winter I keep you warm. What am I? (A tree.)
Alborozar is an uncommon verb that has a connotation similar to "to delight" or "to excite":
- Alborozas cada célula de mi ser. You thrill each cell of my being.
- Se alborozaron con la idea de tener su apartamento propio. They were excited about the idea of having their own apartment.
Placer, related to the English word "please," suggests the giving of pleasure.
- Me place decir que tengo dos. It pleases me to say I have two.
- El recién inaugurado museo tiene dos aspectos que me placieron. The recently inaugurated museum has two aspects that pleased me.
Felicitar is derived from feliz and is included here for that reason. It typically means to wish someone happiness and is often translated as "to congratulate." Me felicitaron por la selección del hotel. They congratulated me for the hotel selection.
Sources: As is the case throughout most of this site, sample sentences are adapted from variety of sources, most of them written by native Spanish speakers. Among the sources consulted for this lesson are: Chocolat Factory, Ciao.es, GestioPolls, El Norte de Castilla, LibrePensar, Pompeyo Carrasco, Sergio Vargas, SDPnoticias, Taringa.net, TripAdvisor.es, Tu Breve Espacio, Twitoaster.com.