I have the following question. In the sentence:
I personally believe that the kids need more discipline
Is the grammar correct?
Best Regards and thanks!
And if you must put "Best regards" at the end of your posts (which is completely unnecessary), do not capitalise "regards".
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
Nikitus, I expect it's different in Spanish, but the definite article before 'kids' narrows it down to a previously specified group of two or more children.
Omitting 'the' would mean you believe all children need more discipline.