Compra-lo and Ve-lo (object pronoun -lo)

[jan]

I understand “you have to buy it” can be “tem de compra-lo” - are these following modifications OK:
Tenho de compra-lo
Tenho de compra-los

and

I have to see it:
Tenho de ve-lo
Tenho o de vir

[Joseph]

@jan

I understand “you have to buy it” can be “tem de compra-lo” → correct, if this the formal & singular you (você). the informal & singular (tu) would be “tu tens de comprá-lo”- are these following modifications OK:
Tenho de compra-lo → This is a different subject. It means “I have to buy it”, not “You have to buy it”
Tenho de compra-los → This is both a different subject and a different number of objects. It means “I have to buy them”, not “You have to buy it”

and

I have to see it:
Tenho de ve-lo → correct (don’t forget the accent: vê-lo)
Tenho o de vir → in this case, vir is the infinitive of a different verb (to come), so it’s not applicable here. Also, object pronouns must be next to the respective verb. So, you can write “Tenho de vê-lo”, as you did above, or “Tenho de o ver”. “Tenho o de ver” is grammatically incorrect.

@jan, I added my comments over your post, hope it’s clear. Also, for reference, here’s a helpful Learning Note about object pronouns (which is the opener for the respective unit): Object Pronouns in Portuguese

[jan]

Muito obrigado! Tudo compriendo…