Up until a couple of hundred years ago (and even now in some dialects) English used to have informal second person pronouns, which were "thou" in the singular and "ye" in the plural. And the "thou" form was indeed inflected ("thou lovest" etc.). But that's seen as archaic in standard English, and now people just use "you", which was the previous polite form, in all circumstances, in both singular and plural, and with no distinction in the verb form from the other plural forms. But you will come across these forms in older literature, such as Shakespeare.

You just use "you," always lower-case except as the first word of a sentence, and you send the appropriate social signals with other words and language--such as "being on a first-name basis."

In American English, we do not differentiate. You means you in all contexts.