Unlike English, there are two verbs that translate into Spanish as 'to be'. Getting this difference right is one of the hardest things for a learner of Spanish to learn. You would use 'ser' for more permanent states of being such as in the following six uses: 1) Descriptions e.g. Soy Tom (I am Tom), Es español (He is Spanish). 2) Occupations e.g. Mi padre es médico (My father is a doctor). 3) Characteristics e.g. Eres inteligente (You are clever). 4) Time e.g. Hoy es jueves (Today is Thursday), Son las diez (It is 10 o'clock). 5) Origin e.g. Soy de Canadá (I am from Canada), La silla es de madera (The seat is made from wood). 6) Relationships e.g. Es mi marido (He is my husband). You would use 'estar' for more temporary conditions such as in the following five uses: 1) Position e.g. La puerta está cerrada (The door is closed). 2) Location e.g. Estoy en Madrid (I am in Madrid). 3) Actions i.e. the Present Continuous Tense e.g. Estoy comiendo un plátano (I am eating a banana). 4) Conditions e.g. Está cansada (She is tired). 5) Emotions e.g. Estamos muy contentos (We are very happy).