But there is also this "בתוך" word I've heard, what does that mean?
Well, that's easy. :)
We have "ב-" (BE-), meaning "in"
and we have "בתוך-" (BETOKH), meaning "inside," this simple. :) "Inside" just has a stronger emphasis, that's all!
For example:ילדים, אסור לשחק כדורגל בתוך הבית! תצאו החוצה!
Kids, you can't ("it's forbidden") to play football inside the house, go outside!
אמא, איפה היוגורט? היוגורט במקרר, כמובן.
Mom, where is the yogurt? In the refrigerator, of course.
There is more to say about the "outside" words... But that - in the next email!
Looking forward to the next week!