Using Ser and Estar: Different Meanings Depending on Verb Used

Both verbs ser and estar mean "to be" and are an integral part of the Spanish language.  After all, we use the verbs "is" and "are" frequently in the English language, as well.  The difference between both languages is that we only use one verb versus the two for Spanish.  

While we only need to use one verb in English, some sentences in Spanish change meaning depending on whether ser or estar is used.  Here is a list of important differences in Spanish.  While this list is not all-inclusive, it does include the vast majority of the commonly used phrases that change depending on whether or not ser or estar is used: 

Yo soy listo.  I am clever.   

Yo estoy listo.  I am ready (prepared).  

La manzana está verde.  The apple isn't ripe (unfit to eat).  

La tortuga es verde.  The turtle is green.  

Bill Gates es muy rico.  Bill Gates is very rich.  

El mole está muy rico.  The mole is very tasty/delicious.  

El Honda nuevo es muy seguro.  The new Honda is very safe.  

¿Estás seguro que el jefe no viene hoy? Are you certain that the boss isn't coming today?  

El niño es muy malo.  The kid is very bad (he's a bad kid).  

Jaime no se siente bien.  Está muy malo hoy.  Jaime doesn't feel very well.  He is very sick today.  

La profesora es muy aburrida.  The professor is very boring (is a boring person).  

Estoy aburrido.  Vámonos a hacer algo.  I am bored.  Let's go do something.  

Hope this helps.  ¡Ojalá te ayude!