Can I ignore parts of words to make valid words?

Question

In scrabble can you form a word ignoring the last letter of a word on the board.

Ex. REEK is on the board Then I add T, to form TREE, ignoring the K. It looks like this on the board: TREEK

Answer 1

No

Every word you form has to be a valid word, including all letters immediately to the left and right of the letters you put down or immediately above and below. Or both - e.g., a single letter could "connect" two existing words, one horizontal and one vertical, forming 2 new words. Unless the players agree on a dictionary that has "TREEK" in it, your example doesn't work.

More critically, let's say the K was a blank used as a K. You can't put down a "T" and then say "I want to turn that 'K' into a 'D' to make 'TREED'." Once a blank is set as a particular letter, it is treated as that letter for the rest of the game.