If you aren't sure which of two possible spellings is right, you can use the spell command with no arguments to find out. Type the name of the command, followed by a RETURN, then type the alternative spellings you are considering. Press CTRL-d (on a line by itself) to end the list. The spell command will echo back the word(s) in the list that it considers to be in error:
If you're using, you need to add the -l option, since ispell doesn't read from standard input by default. (Even -l doesn't let ispell read from a pipe. The purpose of this option is to let you type in a list of words, just as shown above for spell ; when you end the list, ispell will echo back the misspelled word, just like spell . There's no additional functionality there, except that ispell will use its local dictionaries and improved spelling rules.)
An even better way to do the same thing may be with . With just one argument, look searches the system word file, /usr/dict/words , for words starting with the characters in that one argument. That's a good way to check spelling or find a related word:
look uses its -df options automatically when it searches the word list. -d ignores any character that isn't a letter, number, space or tab; -f treats uppercase and lowercase letters the same.