In speller I get a segmentation fault, what is strange that when i run the programm through valgrind it doesn't crash... In GDB I backtraced that there is a problem when trying to free(woord2). Anybody see the problem? In the light of academic honesty i just posted the part I think is important, if something else is needed, please let me know. https://gist.github.com/anonymous/177eed6b6faf9750602e
Answered in comments by Cliff, OP's problem solved.
Strings, in C when using strlen and strcpy, are considered as NULL terminated character arrays which we happen to call strings. If your going to use the string functions be sure your character buffers are large enough to account for all characters and the terminating NULL.