Did you teach your children how to speak their native language in classroom with grammar lessons? Or did you teach them by pointing and showing in your own home?
Did you grasp the basic grammar of your native language before you spoke it at about age 5?
I have university degrees Biology, Computer Science and Geology. I've written professionally and am astonished that we teach foreign languages in school and college the opposite way to which learn our native languages.
I to used to translate from Polish into English and back again and wondered why could not keep pace with Polish conversations.
These courses will show you why you can't keep up with English conversation.