While surfing the internet the other day, I came across several videos on YouTube which discussed the form of address (formal vs. informal) that should be used when ordering food in a restaurant and from a food truck. (The food truck was specific to Mexico but the restaurant location was more general — it was left open as to where in the world you were located. It could have been anywhere, in my opinion.)

I have seen the typical/standard/usual explanations in dozens of textbooks and on internet language learning sites of when to use Usted vs. tu and they all basically say the same thing and I have never had any problem with the usage or the concept.

The statement was made that the informal form of address (tu) was to be used to the operator of the food truck by the client, regardless of the age/status, etc. of the food truck operator. This to me was something new in terms of the usage. This is completely situational. It has to do with the situation and none of the “explanations” that I have previously seen in books and language learning sites apply here.

Similar usages were suggested for bar and restaurant contexts, although there was not 100% agreement on this.

Or is it simply the case that waiters, bartenders and the owner/employees of the aforementioned food truck are addressed with “tu”?

I know that there is (or was, at least at one time) a tendency for similar social groups to immediately use “tu” with each other — students at the university, for example. Here adults, though not close friends, at least from the start, tended to not use “Usted” with each other.

Let me give an example or two to clarify my understanding/confusion and dilemma.

Does a 10 or 12 year old native Spanish speaking girl address all of these people with “tu”, no matter how old they are?

Does a 50 year old man who is a native Spanish speaker address all of them with “tu”, no matter their age?

Or do both situation and age play a role here?

I am assuming in all these examples that none of these people know each other.

Many thanks to all and hello from Chicago.