HAS TO - HAVE TO : TENGO QUE,TIENES QUE TIENE QUE,TENEMOS QUE,TIENEN QUE.
HE - SHE - IT ( HAS TO ) WE - YOU - THEY (HAVE TO )
EXAMPLES:

MARY HAS TO CLEAN HER ROOM EVERY WEEK- END

THE CHILDREN HAVE TO PLAY OUTSIDE THE HOUSE

DOESDAVID HAVETO SOLVE THE PROBLEMS BY HIMSELF ?

YES, HE HAS TO DO IT / NO, HE DOESN'T HAVE TO DO IT.

HAD TO : TENIA QUE,TENIAS QUE, TENIAN QUE,TENIAMOS QUE.

DID YOU HAVE TO VISIT YOUR FAMILY LAST WEEK?
YES, I HAD TO / NO, I DIDN'T HAVE TO

WILL HAVE TO: TENDRE QUE,TENDRAS QUE, TENDRA

WHERE WILL THE MAN HAVE TO WORK NEXT YEAR ?

HE WILL HAVE TO WORK IN FORD COMPANY
I THINK HE WON'T HAVE TO DO IT ANYMORE

GOD BLESS YOU ALL DEAR STUDENTS SEE YOU!