As WordSmith works its way through text files, or re-sorting data, you will see a progress window in the Controller with horizontal bars showing progress. If appropriate there'll be a Suspend button, too. Pressing this offers 4 choices:
... as if you had not interrupted anything
stop after this file
Finishing the file means that you can keep track of what has been done and what there wasn't time for. (How? By examining the filenames in the word list, concordance or whatever you have just been creating.)
stop as soon as possible
...useful if you're ploughing through massive CD-ROM files. WordSmith will stop processing the current file in the middle, but will retain any data it has got so far.
Press Suspend again to effect your choice.