There are 18 words that start with 'know'.
| know | known |
| knows | knower |
| knowns | knowers |
| knowing | knowable |
| knowings | knowinger |
| knowingly | knowledge |
| knowingest | knowledges |
| knowingness | knowingnesses |
| knowledgeable | knowledgeably |
Note: These 18 words that start with 'know' are found from the USA & Canada version of the tournament Scrabble word list.