# data[].attributes.body
My father grew up in Mexico (his family is not Mexican but my grandparents moved there before he was born, long story...) but anyway I was raised speaking Spanish. Occaisonally I speak to his family in Spanish but have used the tu form when addressing them. I learned that the Tu form is used for family, including grandparents.

# data[].attributes.body
People will probably think I'm crazy, but I think it does depend on the family and the way you were brought up. If you are an English speaker and need a guideline, maybe this would work: use Ud. with anyone that you would use "sir" or "ma'am" with in English. This includes parents and grandparents, if you call/use "sir" and "ma'am" with them. Most people I know are NOT on "first-name basis" with parents and grandparents, but I think that's slightly different.

# data[].attributes.body
I have seen my parentes addressing my granparents -their parents- by using USTED, but I have never addressed them using that way, always TÚ.
That happened in Spain, where it was very common that sons addressed their parents with "usted". It depends on the country.

Un saludo.

# data[].attributes.body
In Venezuela, los 'gochos' (la people from the Andes mountains) often use 'usted' to refer to anyone in their families. So the grandparents call the little children usted!

Because people in other parts of Venezuela don't speak like that, some of the Andinos change the way they speak when they come into other settings, like the university. But at home everyone is still 'usted'.

# data[].attributes.body
I use both with my grandma, depending on what I'm saying, which is probably weird. Pero creo que siempre he dicho ¿cómo está? en lugar de ¿cómo estás? con ella.
(But I think I have always said ¿cómo está? instead of ¿cómo estás? with her.)

# data[].attributes.body
Hi! In Argentina we would never use usted to refer to our granparents because it sounds too formal. We would say "vos" which is the equivalent of "tù" in Spain.

# data[].attributes.body
It depends on the relationship you have with your grandparent. I use 'tú' with my parents and grandmother, but I would never use 'tú' with a person who is older than me that I don't know. If you are unsure, it's always respectful to use 'Usted' first until you are invited to speak in 'tú'. Hope this helps!

# data[].attributes.body
I generally use "Usted" just with someone significantly older than me that I don't know very well.

# data[].attributes.body
In some countries, like Bolivia, you use "usted" as a way to express "cariño" (affection) regardless of age, and you use tú for people you don't know.
In other countries... is the other way around.....

# data[].attributes.body
It depends of the country.
In Chile... if you are a child, you would always use Usted. (así, con mayúscula). But as you grow older, you can start using tú.

# data[].attributes.body
I am Mexican (39 years old) and I used tu with all of my grandparents (two from Spain and 2 from Mexico)

# data[].attributes.body
I always use "usted" when I am talking to my grandparents and uncles (and I am 23 years old). It has always been that way in my family.

# data[].attributes.body
I'm from Mexico and even though I use "tu" with my parents, I never used "tu" to address my grandparents, I always used "usted". It was just a form of showing respect. In fact, the only people I use "tu" with which are significantly older than me are my parents, I also address my aunts and uncles with "usted".

# data[].attributes.body
Unless it's your own grandparent, in which case use "tú"

Use varies from country to country, but normally you would say "tú" because you
are obviously on first-name terms and have a close relationship, and their age has nothing to do with it. I have never met anyone who calls their own family "usted."