The script I wrote conjugates the verbs in the present tense. What makes you think it conjugates the verbs in the past tense? It would be trivially easy to make it conjugate the verbs in the past tense (just change "present" to "past" in my program) but that is not the issue.
The issue is - in my opinion - that even if you make your program run, it will still not run correctly, as it does not take into account how to deal with irregular verbs or certain well-known grammatical exceptions. If you wish to take care of that, then you will end up with a program very similar to mine.
A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James
My blog: Imperial Deltronics