In English, the second-person pronoun is “you”.
In Hindi, we have three equivalents for this: तू tu, तुम tum, and आप aap.
The first one is तू tu.
तू भगवान् है – tu bhagvaan hai – you are god
तू रवि है – tu ravi hai – you are ravi
तू मेरा बेटा है – tu mera beta hai – you are my son
तू एक बेवकूफ है – tu ek bevakoof hai – you are an idiot
Tu is the intimate pronoun. We use this with whom we are intimate. This is generally used to address close friends, children, servants, and wife. In religious contexts, tu is often used to address God. Tu is also used when expressing anger or insult. And if you are a foreigner, try to avoid tu at any cost.
Tu is always treated as singular and hai है is the “to be” verb that comes with tu. Hai is “is” but assumed as “are” in these sentences.
The second one is तुम tum.
तुम शिल्पा हो – tum shilpa ho – you are Shilpa
तुम बुद्दिमान हो – tum buddhimaan ho – you are intelligent
तुम बूढ़े हो – tum boode ho – you are old
Tum can be used in all informal situations except addressing elders. The “to be” verb that comes with tum is हो ho. Ho is are. Tum may refer to one person or more than one person. Whether tum is used for one person or more, it is always treated as plural. Therefore the adjectives and verb forms used with tum are in the plural.
So the sentence तुम अच्छे छात्र हो – tum acche chhatr ho can mean “you are a good student” or “you are good students”.
The third one is आप aap.
आप मेरे पिताजी हैं – aap mere pitaajee hain – you are my father
आप अब्दुल हैं – aap abdul hain – you are Abdul
आप अच्छे हैं – aap achche hain – you are good
Aap is respectful and formal. It is used for seniors, elders, strangers who are both younger and elder than you. If you are a foreigner, then better use aap in all situations.
Aap can be used to address one person or more than one person. Whether aap is used for one person or more, it is always treated as plural. Therefore the adjectives and verb forms used with tum are in the plural. The “to be” verb used with aap is हैं hain.