Question concerning SPELLBOUND…please help

Hello fellow gamers!  How’s everyone doing?   Good, I hope. 

I got a question about SPELLBOUND:  Does anyone know if ALL the letters in each round absolutely makes a word? 

Seven positions or letters are provided and we make words using all seven letters.  Of course, timing is considered (how fast you make a word) as well as the length (has to be at least three letter word) and the difficulty of the letters that are used to make a word (for instance, Q, K, or Z, etc.). 

In each segment or ROUND of the game — does all the 7 letters spell a word ONCE each time? 

OR IS IT POSSIBLE during a game THAT THE SEVEN LETTERS PROVIIDED CANNOT make a word???  

Does the game allow letters in each round ( whereas one or more rounds of the game)—a seven letter word is not possible??? 

Is there ever a case in which all seven letters will not spell a word during a round?

There is always a ( highlighted or yellow?)  alphabet in the seventh position to make a word

(this letter adds more points than the letters in the first six positions). 

I would appreciate if anyone let me know whether or not  it’s absolute that a 7 letter word can be made ONCE during each round of the game.  I took for granted that ALL these seven letters will make a word each time at least ONCE during a round in a game.  

Thanks in advance for your help and clarification on this.