Form vs Content
First is the different things my children and I pay attention to. Here's an exchange between my son when he was nine, and me:
Son: And then I hear-d the teacher say... ["Hear-d" here sounds like "heerd".]
Me: I heard.
Son: What did you hear?
Well, apparently I am concerned with the form, while he listens to the contents. Of course, even though he got the past tense form of "hear" wrong, he had no problem with parsing the correct form "heard" that I used. So, when I go through all the "irregular" verb tables I had to memorise, and all the rules from Murphy's books, my error detection circuits running on full steam, while he's just speaking and listening.
Also, you know there are two (main) Englishes in the world: the "English" (British) English and American English. The former might be extended to something called European or Euro-English if defined as basically any English that is not American...
Anyway - we live in Ireland, so theoretically my children should speak the European form of English, peppered with all those nice Irishisms, and they should adhere to the British spelling rules.
As it happens - again - I'm the biggest "grammar Nazi", or actually the "language Nazi" here!
Take the spelling of the "-re"/"-er" morpheme. My son's doing his homework and writes "meter". I say: "This is very good, but this is American spelling, here it is spelt (!) 'mee-truh'". This is all good and well, but you have to realise that my native language's spelling system (in Poland it's called "orthography") is much more phonetic than that of English. So for me, who learned English mainly by writing it, the difference between "metre" and "meter" is quite obvious, just like between "your" and "you're". For a native speaker these words sound exactly the same, though - and metre/meter might as well be spelt/spelled "meetur". No wonder I have to pronounce it "mee-truh" (something that sounds like 'mitrah') to convey what I'm about.
And then I read some notes from the teacher, and see, that not even teachers can spell properly. Plus - come on, I myself prefer "spelled" to "spelt", and "plow" to "plough". And "curb" to "kerb"!
Spelling is actually the easier part, anyway. After all - it (usually) sounds the same when pronounced, so what's the big deal? As long as you don't spell "train" as "chrain" (which has actually happened!!!)
My daughter, at about four and a half years of age, learns a lot of words from youtube videos. Needless to say, most of those videos are American, just like the rest of the Internet. So when she once found a dummy in a box of old stuff, she told me:
Daddy, look, I found a pacifier!
So I go on to explain that here it is actually called a "dummy"...
No, daddy, look, it's a pacifier. You know, for babies.
Yes, honey, I know, it's just that Americans call it a pacifier, but here in Ireland it's called a 'dummy'...
Daddy, when there's a baby in mummy's (or did she say "mommy's"?) belly, when it comes out, we can give this pacifier to him, and we will have to change his diapers.
Yeah, they're actually called 'nappies'... Oh, never mind.
You want fries with that? I mean chips. Or crisps. You know what, let's have potatoes.
And don't even get me started on the fries vs chips. See, this is really really difficult for a foreigner in Ireland, because it's not as clear cut as AM fries = BR chips.
Chips in Ireland (and the UK) are long, deep-fried potato pieces, served hot. And fries are also long, deep-fried potato pieces, but they are much skinnier. Americans allegedly call those "steak fries".
The thin slices of potato served cold are called crisps here, which is fine, except that in Polish these are actually called "chipsy" (or "czipsy"). And then you go to a shop and you find these:
which are absolutely delicious Kettle Chips crisps.
To make things worse - having crisps as a side with your lunch is perfectly normal here. So if your child asks you: can I have chips with this - it can be difficult to get it right...
Then there are the nursery rhymes. How does a child learn the English alphabet? Of course, by singing "ay, bee, see, dee" to the tune of "Twinkle Twinkle Little Star". At least that's the way in... the United States of America, because "vee" rhymes nicely with "zee".
Now, try and explain to a child that the song shouldn't actually rhyme, because the last letter of the alphabet is called "zed".
In general - parents raised in a different language have a tough job with English nursery rhymes, because... they never learned them. More or less, the first time I'd heard "Humpty-Dumpty sat on a wall..." was when watching this:
The fact that this comes to mind first when Humpty-Dumpty is mentioned, or all the other rhymes that scarcely make any sense, doesn't really help when a four-year-old is yelling at you something like:
Daddy, sing it! Sing now! But I don't know the lyrics, I don't know this rhyme! How can you not know, didn't you go to school?!? Now, sing!
See, the problem is that most nursery rhymes are not even supposed to make sense, just rhyme (hence the name). That's great, but for an adult it is easier to learn something that makes sense...
But some of them do, for example: "Hickory, dickory, dock, the mouse ran up the clock" - this is not gibberish; these are numbers eight, nine and ten used for counting sheep and playing games in the Celtic languages spoken on the British Isles before the Angles, Saxons and Jutes came there - which were something like "hovera, dovera, dick".
Oh, that helps a lot, now I know all the twelve stanzas of this great nursery rhyme...
In Ireland there is also this bonus for foreign parents, where children learn the "native" language of Ireland called... Irish. Yes, such a language exists, and is also called Irish Gaelic (but don't use this name when talking with Irish people - for them it is Irish, end of story). Not many people can speak it fluently, not to mention having it as their native language. It might be because it actually died more than a century ago... It is however being revived vigorously, and part of this activity is it being mandatory in school.
Anyway, children who learn this "native" Irish language in schools sometimes require some help from parents with their homework. Well, could there be a better opportunity for an amateur linguist like myself, to find out more about this beautiful Goidelic language?
Here's how one of such opportunities went.
There is this Irish word spelled 'ubh', and it sounds something like 'oov' (the 'oo' sound being the one if 'foot': /ʊ/).
Me: Do you know how to remember that? This is like the word for egg in Latin: 'ovo'
9-year-old son: Yeah, great, dad, that'll help me, all I need is to learn Latin first...
So I went further, to relate this to his native English:
Me: You know what ovulation is? When a woman produces eggs - "ovo" - "ovulation"
To which my son replied with a hint of disgust on his face:
Son: Now I have NO IDEA what you're talking about!