Absolutely, this is one request that the schools usually like to get. They would rather know, in advance, if two kids don't get along.

After my DS had some conflicts with another child in his K class, I asked the Asst. Principal if it would make sense to separate them the following year. He laughed and said that they were already on the "list". He said that they keep a list for each grade of the kids that probably shouldn't be placed together. This is apparently pretty common.

I would just describe the dynamic and not put blame on either one. Sometimes 2 perfectly nice kids can get together and become partners in crime.

A friend and I were thinking of saying our boys shouldn't be together. We didn't do it and now I am so glad we didn't. The school year has gone great. It was really nice for them to have a familiar face in the class. It really helped with Kindergarten transition. Also, the teachers are really good at placing certain kids at tables together and changing that throughout the year if issues arise.

If it were a 'nasty' type thing---kid a bully to your kid--you could say something. However, if it just that they have fun, talk, etc..schools are pretty adept at handling those situations. There also can be a lot of maturing that happens between now and next September.

My DDs school used parent input forms. We could not specify a teacher but could write what kind of qualities in the teacher we thought would be a good fit (ie - has a more free-flowing classroom or is organized, has a routine and is more strict etc..)

My neighbor had a DD the same grade as mine was was always trying to compare her "better/more advanced" DD to mine so on the parent input form I wrote, "Juliette and Morgan spend so much time together outside of school I wish to request that they not be placed in first grade together so they can expand their friendships." The teacher had no problem with that.

Yes, you can. I did. It worked.

Absolutely tell them. Believe me, the school does not want "bad combinations" together. I taught first grade and at the end of the year, we always made comments about kids who should not be together the following year. Lots of different reasons.