Modals Verbs

All the auxiliary verbs except be, do and have are called modals. Unlike other auxiliary verbs modals only exist in their helping form; they cannot act alone as the main verb in a sentence.

Be, do, and have also differ from the other auxiliaries in that they can also serve as ordinary verbs in a given sentence.

The modal verbs are:-

CAN / COULD / MAY / MIGHT / MUST / SHALL / SHOULD / OUGHT TO / WILL / WOULD

sentences

°in china you should bowing for respect - en china tu deberias hacer reverencia por respeto

°you have to make the homework to win the year - tu tienes que hacer la tarea para ganar el año

°they must start to study - ellos tienen que empezar a estudiar

°you should make the homework - deberias hacer la tarea 

°I have to draw a rose to my girlfriend - tengo que dibujar una rosa para mi novia 

°you must practice sports - tienes que hacer deporte

°we should read to learn - tenemos que leer para aprender 

°you have to sleep 8 hours - tienes que dormir 8 horas

°I must eat to survive - tengo que comer para sobrevivir 

°he shouldn't be builder - el no deberia ser constructor