A 2 year old that doesn't let you change his diaper can be simply that he hates diapers and wants to be potty trained or he's just too distracted by what he's currently doing and hates being removed from his activity to be changed.
Give the 2 year old a warning about it being soon time to change his diaper such as say in 5 minutes we will change your diaper and then remind in a few minutes later before then.
Then take the 2 year old to where you change diapers and try singing to them or giving them a toy to play with.
Or if you have too then you should hold them down until the diaper is changed.
You could try potty training him and tell him that he won't need his diaper changed if he starts using the potty.
If he's still not ready to potty train and still hates getting his diaper changed then it can simply be that he hates being taken away from whatever he's doing to have the diaper changed.
Many kids put up a fight about diaper changes even when they are not potty training ready.
Sometimes its just a phase they go through but you can try distracting him with a phone, tablet, toy etc until you get his diaper changed.
If he's not poopy you could try doing a standing diaper change or change the 3 year olds diaper wherever he is at at the time if possible.
Between 40 percent to as much as 60 percent of 3 year olds are not potty trained and still use diapers.
The majority of children are still in diapers full time and not potty trained by 3 years old and some are still in diapers until age 4 to 5 years old.
The age that a child should be potty trained by is around 3 to 4 years old although it's okay if the child is not ready for potty training by age 5 and a 1/2.
Some kids are not ready to give up diapers and go potty in the toilet until they are 5 years old or a little over 5.
However the majority of kids will be potty trained by 2 to 3 years old but every kid is different.
It is normal for a 5 year old boy to wear diapers and to not be potty trained.
While some kids may potty train by age 2 to 3 years old it's perfectly normal and okay for a 5 year old boy to not be potty trained and wear diapers instead.
Some kids may not potty train until a little after their 5th birthday which is also okay.
The age that you stop putting your child in diapers is when they are between the ages of 3 to 4 years old or when they are potty trained.
Some children are potty trained before age 3 and some by age 18 months to 2 years old.
The age at which children are potty trained and stop wearing diapers varies depending on the child as all children are different.
While one child may be ready to potty train at 18 months to 2 years of age, some children may not be ready to potty train and stop wearing diapers until age 3 to 4 years old.
And in some cases a child may not be fully out of diapers and be potty trained until they are 5 years old or 5 and 1/2 years old.
There's no set age that a child has to be potty trained by and it's really up to the child as to when they will get out of diapers.
If you wait until the child is at least 3 years old or 3 and 1/2 the potty training for the child usually is faster and goes much smoother without many accidents.
Potty training before 3 years old means that you will be dealing with a lot of wet pants and pooped in pants as well as furniture floors etc.
Keep the child in diapers until they are ready and don't force them into potty training too early as it can lead to more problems.
If your child is refusing to potty train then you should wait a few months to try again.