Hi May,
I've been looking this one over for a while, and although it looks like these two sentences are independent they actually are not.
There are specific and complicated rules to American English grammar as you know, this is just one of those rules:
A complete sentence should be able to stand alone and make complete sense by itself.
Example, if you read this sentence in the paper it makes sense.
"Mom killed three aunts". It's fine just like that.
If you read this one in a news paper it would not make any sense by itself.
"They were eating our sugar in our kitchen."
There are other ways to shorten this, and for it to still make sense, but to simplify for your young son for now, just put a comma between the two parts instead of a period.
"Mom killed three ants, they were eating our sugar in our kitchen."
I've been looking this one over for a while, and although it looks like these two sentences are independent they actually are not.
There are specific and complicated rules to American English grammar as you know, this is just one of those rules:
A complete sentence should be able to stand alone and make complete sense by itself.
Example, if you read this sentence in the paper it makes sense.
"Mom killed three aunts". It's fine just like that.
If you read this one in a news paper it would not make any sense by itself.
"They were eating our sugar in our kitchen."
There are other ways to shorten this, and for it to still make sense, but to simplify for your young son for now, just put a comma between the two parts instead of a period.
"Mom killed three ants, they were eating our sugar in our kitchen."