Answer:
Nosotros tomamos agua purificada
Sergio baila tango
Tu tocas el piano
Step-by-step explanation:
Remember in Spanish each pronoun as a specific ending for verbs.
Nosotors - ..mos: Tomar = toma + mos = tomamos
Sergio (el) - ...[remove the -r): bailar => baila
Tu - ...s: toca + s = tocas
Of course, you will find irregular verbs that may complicate things a little but they still follow a recognizable pattern.