Definition - Verbs are words that describe a state of being or an action. Examples of Spanish verbs are:
             • ser [to be], tener [to have], ir [to go], hacer [to make], escuchar [to hear], partir [to leave], ...

Types - There are several kinds of verbs. The following definitions refer to the most used terms in grammatical explanations.

Infinite verbs only name the state of being or action, without giving other information:
             • Necesito comprar el periódico. [I need to buy the newspaper.]
             • Lola va a tomar un curso de inglés. [Lola is going to take an English course.]
             • Quisiéramos beber café, por favor. [We would like to drink coffee, please.]

Infinite verbs can be conjugated into finite forms. Finite verbs not only name the state of being or action, but also indicate who performs the action (the subject) and when the action is performed (e.g. present, past, future).
             • Yo leo una carta. [I am reading a letter.]
             • Manolo tiene un coche amarillo. [Manolo has a yellow car.]
             • Bebemos el café. [We drink the coffee.]
             • Ayer usted compró un libro. [Yesterday you bought a book.]
             • Van al cine mañana. [They will go to the cinema tomorrow.]

Transitive verbs name actions that 'aim' at an object, either a thing or a person. These verbs need an object to be complete and make sense. Verbs like 'hacer [to make]' or llevar [to wear]', for instance, do not make sense unless we know what is being made or what is being worn.
             • Carmen hace el café. [Carmen makes the coffee.]
             • El señor Díaz toma el taxi. [Mr Diaz takes the taxi.]
             • Felipe lleva un traje azul. [Felipe wears a blue suit.]

Intransitive verbs do not 'aim' at anything or anybody. Verbs like 'caminar [to walk]' or 'volar [to fly]' describe actions that do not have an impact on an object.
             • Miguel camina. [Miguel walks.]
             • Este avión vuela. [This plane is flying.]

Note: some verbs can be both transitive and intransitive.
             • Correr en una carrera. [To run in a race.]
             • Correr un riesgo. [To run a risk.]

Use - Regular verbs conjugate into the various finite forms according to a fixed pattern. If we know the infinite form of a regular verb, we can conjugate the verb following this regular pattern. In Spanish this means that we delete a certain ending from the infinite form and replace it with other endings.

An example of Spanish regular verb:
             • Infinite - hablar [to speak]
             • Conjugation - yo hablo [I speak]
                                    - tú hablas [you speak]
                                    - él/ella habla [he/she speaks]
                                    - usted habla [you speak - polite form]
                                    - nosotros hablamos [we speak]
                                    - vosotros habláis [you speak]
                                    - ellos/ellas hablan [they speak]
                                    - ustedes hablan [you speak - polite form]

Irregular verbs, on the contrary, do not follow a regular model.

An examples of Spanish irregular verb:
             • Infinite - ir [to go]
             • Conjugation - yo voy [I go]
                                    - tú vas [you go]
                                    - él/ella va [he/she goes]
                                    - usted va [you go - polite form]
                                    - nosotros vamos [we go]
                                    - vosotros vais [you go]
                                    - ellos/ellas van [they go]
                                    - ustedes van [you go - polite form]