In 1st person singular. it is voy (I go)

2nd person singluar is vas (you (1 person) go)

3rd person singlular is va (he, she or it goes (or you (polite) goes))

1st person plural is vamos (we go)

2nd person plural is vais (you (more than one person) go)

3rd person plural is van (they (or polite you pl.) go)

van=they go

vas= you go

va = he/she/.it goes

¿Adonde va? : where is he/she/it going?

¿Adonde vas?: where are you going?

¿Adonde van?: where are they going?

¿Usted van al medico conmigo? : are you going to the doctors with me?

Ir is the verb to go, which is used more in the present and future. Va, vas and van ae used also in the present asking where he,she, they are going which is third person singular and plural.Present Indicative.

A donde va? Where are you going? To any person.

A donde vas? also Where are you going? the difference between vas and va is you use va for one person-he/she of anyone with out mentioning names, then vas if you say a name, examples:

To anyone one A donde va?

To John or Mary A donde vas John/Mary?

Or if you want to you can look at that person and omitt the name.

As for van it is A donde van? When you ask various persons at the same time where they are going.

Now for the doctor you will say:

Vas al medico conmigo? Here you are saying Will you go with me to the doctor with me? Vas because you are talking to some one you know and you are inviting them to acompany you.

Now if you use usted which is formal for you because you talk to that person for respect, if that person is older than you or that person you just met so your question would be:

Usted ira conmigo al medico? Here ira comes from ir which is to go. I used ira because usted (you in a more formal respectful way) is being used to talk to that person.

yo voy = i go

tu vas= you go

ella /ello /usted va = she/he/ goes.

nosotros vamos = we go

vosotros vais = ya’ll go

ellos/ellas/ustedes = they go (group )

ir is a the spanish verb to go those are the present tense congegations of the verb. its irregular hence the odd spelling.