If you were to type "bookbag" (one word) into most computers with Spell Check on, it would catch it, and in most - but not all - dictionaries it is listed as two words.
However, because the English language is so complex and is constantly changing, it would normally be perfectly acceptable to write bookbag as one word in this day and time. Everyone would understand exactly what you meant and I can not see any copyeditors (<-- there's another debatable word) throwing a fit over it.
As far as most people are concerned, "bookbag", "book-bag", and "book bag" can all be considered correct and entirely interchangeable.
A good rule of thumb would be that if you do not feel the absolute need to hyphenate or space out a compound word, you probably don't need to. This is how new words are created and/or modernized in the English language after all.
These days, it is one: Notebook. It hasn't always been that way, though.
Backpack is only one word :)
Sketch book
One.
2 words
book-bag, or book bag. it is two words, but it can be one if you use a little slash-y thing.
"Bookstall" is two works: Book Stall.
There are two syllables in the word 'bookcase'.
According to OED it is spelled 'log-book' .
It can be one word and two words it just depends on how you are using it. As a noun it is one word. If "flow" acts as a verb (for example, "the work flows well"), use two words.
book-bag, or book bag. it is two words, but it can be one if you use a little slash-y thing.
two
Two
"Textbook" is one word. With only two of the letter 'o'.
"Bookstall" is two works: Book Stall.
There are two syllables in the word 'bookcase'.
According to OED it is spelled 'log-book' .
Factbook is one word. Both on the website and offline.
The German word 'buch' translates into English as book. As in the English language it can mean a book which one reads or to book a hotel room for example.
Hand-Bag has two syllables.
infinitely. I would recommend that you word this question exactly how you read it, so you can get a proper response.
No. It is a compound word made from book+keeper. There is only one P.