Yes, it can be challenged if the word is actually invalid.
Forfeit a turn.
Look up the word in a dictionary. There is an official Scrabble disctionary but any normal disctionary will do provided all players agree to use it.
Yes, but it can easily be challenged off because "OK" is an abbreviation that is not listed in the OSPD or TWL lexicons.
When a player challenges a word and the word is valid, the player who challenged loses their turn.If the word is not valid, the player who was challenged must remove their tiles from the board and lose their chance at placing a word.
It depends, as long as it is done in each turn then it is allowed.
Can "principle" be used as a plural? I don't know but if not how can one answer a question about a sentence if the question is worded incorrectly? Maybe the word is pluralized without an "s" in some cases. Regardless, I don't know the major principle(s) of a sentence but I'd guess that it has to start with an upper case character & end with a punctuation mark. This probably answers a different question though. What do you want? I'm a friggin woodworker not a wordsmith. (although I do pretty well at Scrabble)
Yes, "Scrabble" is considered a valid word in the game of Scrabble.
A Scrabble word is an English word that you can use in the Scrabble game.
Here are my results:Letter Scrabble Wordskernel5 Letter Scrabble Wordsenrolkernekneelkroneleonelonernerol4 Letter Scrabble Wordsenolernekeelkeenkenokernkneekoelkoreleekleerlekelenolonelorelornnoelorlereekreelrole3 Letter Scrabble Wordseekeelekeelkeonereernkenkorleelekneenorokeoleoneorereeroe2 Letter Scrabble Wordselenerlonenooeonorre
6 Letter Scrabble Wordshollow5 Letter Scrabble Wordshollo4 Letter Scrabble Wordsholmhomohowlloommollmoolwhomwool3 Letter Scrabble Wordshomhoohowloolowmhomolmoomowohmohoolmoohoomowlwhowoo2 Letter Scrabble Wordshmholomoohomooowwo
No.
Scrabble ME was created in 2007.