"Where were you the day before yesterday?"
Translation:तुम परसों कहाँ थे?
You can be in hindi tu , tum , aap... depending on the age and relationship with you of the person. ....... You = tu ( for younger brother/ sister and friend of your age group or someone who is younger and familiar to you.) And with "tu" you use "tha" at the end of the sentence Eg. Tu kahan gya tha? (Where had you gone?)....................... You = tum.... ( for a stranger of your age group) here you will use " the " at the end of the sentence. Eg. Tum kahan gye the?. ( where had you gone?)..... You = aap... ( for senior citizens , your teacher, guru, etc. Your parents, uncles, aunts, elder bro/ sis etc. You have to use "the" at the end. Eg. Aap kahan gye the?
The ending of the sentence depends on the addressing. In Hindi, there are three levels of addressing. Level 1- Addressing someone with utmost respect, we use आप and end with थे or थी depending on gender. 'आप परसों कहाँ थे?' (male) and 'आप परसों कहाँ थी?' (female). Level 2- Addressing a stranger, we use तुम and end with थे or थी depending on gender. 'तुम परसों कहाँ थे?' (male) and 'तुम परसों कहाँ थी?' (female). Level 3- Addressing someone you know, preferably your own age or younger, we use तू and end with था or थी depending on gender. 'तू परसों कहाँ था?' (male) and 'तू परसों कहाँ थी?' (female). We can also use आप for Level 2.
Tu तू ( informal) s Singular ,and Tum तुम is plural as a basic rule and it is used as formal for plural/ singular ,both , as well. Is Tum is used, For Elders its always Tum ( singular and formal) Some.times next word decides for plura .. For example Tum Sab ( you all ). Its pleural ... Teeती and Taa ता ,are not used for Pronouns.
तुम कहाँ जा रहे हो। ( where are you going ) Singular
तुम सब कहाँ जा रहे हो ( where you all are going ) - plural
क्या तुम खाना खा कर आये हो ?
Have you had food ? Singular with formal