Most verbs in Spanish, when conjugated, only change their ending: ‘amar’ becomes ‘amo’, ‘amas’, ‘ama’, ‘amamos’, ‘amáis’, ‘aman’. However, some verbs change their stem (the first part of the infinitive form) when conjugated in the singular (all three persons), and in the third person plural. That means the first person and the second person plural (nosotros and vosotros) never change their stem. An example is the verb ‘soñar’ (to dream), which becomes: ‘sueño’, ‘sueñas’, ‘sueña’, ‘soñamos’, ‘soñáis’, ‘sueñan’.