Should he be left handed?

Yes, I have a family member who did pretty much the same as your DGS. No pressure from school or parents to be right-handed. In adulthood they then switched to writing with their left hand!

It may be that your DGS has just found that Life is mainly right-handed and automatically goes along with that for some things.

I'm left-handed and am fairly ambidextrous. Just don't ask me to cut a slice of bread unless you want a wedge!

I have a friend who uses different hands for different things, seems to work fine He writes with his left hand and plays high-standard table tennis with his left hand!

Left footed in football is good. Not so many of them and able to play "on the other side" so to speak.

I am fairly ambidextrous but I do write with my right hand. Both my parents were left handed and I suspect I started off life as a baby being right handed but my mother taught me to knit, left hand, teacher at school to sew, right hand, tennis, right hand, table tennis, left, darts either. Before I broke my ankle, football would be either. I think I am lucky being so ambidextrous because if either hand is injured, it would not be the end of the world. I have heard of stories where at school the child's dominant hand was tied behind his/her back.

I use different hands for different things. I have always operated the mouse on my computer with my left hand, among others. I am essentially right handed.

It is called being cross lateral, so it has a name. Relax into it.
www.netdoctor.co.uk/ask-the-expert/pregnancy-and-family/a9703/what-does-crossed-lateral-mean/

My dad was totally left handed, but ate right handed with his knife and fork round the normal way
I think lots of people can have a bit of both and as long as he's happy with what he uses, no problem

Everyone has preferences for being right or left handed, footed, eyed or eared! They can occur in any combination so it's nothing to worry about.

I have two left-handed daughters, one of whom is very left-orientated, while th other just writes with her left hand and does everything else righthanded.

Both my sons are righthanded but one of them plays left-handed/footed sport.

I use different hands for different activities, and when decorating will paint with whichever is at the best angle for the job in hand - very useful when doing things like window frames

I think I'm pretty much ambidextrous. I use my right hand to write, I crochet right handed also when I eat. I pour with my left hand, iron my clothes, and I'm totally left footed. My DD is right handed for everything except eating ?. I really don't think it matters, as long as we are happy doing things our own way.

That should be my DS!

BIL is totally ambidextrous and at least one other family member is right-handed and left-footed.

Thank goodness children aren't forced to use their right hands these days if they are naturally left handed.

I was born in the early 1940's , and was made to write with my right hand at nursery and school. I can still write with my left hand, and it came in very useful when I broke my wrist playing hockey at school.

Our GS was totally ambidextrous. I found it fascinating to watch him colouring and just switching the crayons between hands. He was out under no pressure from home or school but eventually he favoured his right hand - no idea why. He still sometimes uses his left when colouring.

I am right handed but can only use a knife and fork if the knife is in my left hand. My cousin was the other way around. Just one of those things. At least these days left handed children aren't forced to become right handed.

I'm the same - I write right-handed, but am entirely happy typing left-handed whilst holding a phone to my right ear! I also canoe left-handedly. I describe it as "even-handed" :P
My father was predominantly left-handed, but had been forced into right-handed writing at school. He was a devil on the bowling green, because he changed hands at whim - it meant he could get at angles no-one else could!

Like M0nica, I have mixed laterality, and it sounds as though you have too! There is a learned journal dedicated to the scientific study of laterality, but there's also a lot of nonsense pushed by pseudoscientists about handedness. Your grandson will be just fine!

my oldest grandaughter is left handed - the only one in our family i think. however, although she writes with her left hand, she uses cutlery right handed and, i think, uses a computer mouse with her right hand too.
her other grandmother told my daughter that she should tie my grandaughters left hand behind her to encourage her to use her right hand for writing!!! how glad i am that my daughter ignored that advice.
however my grandaughter is very artistic and draws well - although her mum [my daughter] is artistic too and draws well right handed.
we can all write both left handed and right handed.
while i can't draw or paint to save my life, i can draw detailed plans of homes and gardens [i designed my own garden].
so i'm not too sure how much credence you should put on research - you can make research do anything that you want it seems.

There's a test you can do to see what eye you see with first too. My eldest boy is right handed (but can use left hand), left footed and left eyed. He is creative in thinking, not necessarily in execution and terribly clumsy...we were told that often happens with people who aren't completely right or left sided. I'm the same and my late Grandad too although he was forced to use a right hand when he was young.
My other son is Left handed, right footed and right eyed. I have to say he isn't terribly creative and he is quite clumsy!

The most complex thing I use my hands for is playing piano. There are no left-handed pianos. I find the whole subject vaguely ludicrous.

Do I detect a faint air of condescension? As the meerkat says, seemples-don't read/post.

I write with my left hand, and strangely can only make a phone call at my left ear! I played tennis and hockey right handed, also knit right handed. My poor father was punished at school for being left handed and was not allowed to use his left hand. Because of this, his hand writing was really bad.

Don't worry, DS2 is the same. Except that although he was mostly ambidextrous, I encouraged him t be right handed. He is right as rain today, firmly right-handed, although he is handy with his left hand too. BTW he is dyslexic too - so I didn't want to add to his difficulties.

And, DS2 is extremely good with his hand-to-eye coordination, can juggle with all sorts from fire sticks to balls, and good with Lego etc.

Apparently Nadal does everything with his right hand except play tennis. I think people just do what is comfortable to them.