please what the different between
Bist and sind
They are conjugations of the irregular verb "sein" which means "to be" in German.
ich bin - first person singular "I am"
du bist - second person singular "you are" (note: this form is used with family or friends, it is informal and not used with strangers)
er/sie/es ist - third person singular "he/she/it is"
wir sind - first person plural "we are"
ihr seid - second person plural "you are" (again, this is informal)
sie/Sie sind - third person plural "they/you are" (Sie is the formal "you" and is used to address people that you do not know very well.
gramer example ; ich bin = I'am / Du bist = you are / wir sind,sie sind we..vs