Is there any programs on the net that will let you covert text into different tenses?

Question

A story converter.

Answer 1

Probably not since the English language is fairly complexand writing a program like this could take a long time. There are an awful lot of irregular verbs, and the program would have to include them all, as well as other grammatical points to be taken into account.

If you're thinking of writing one, here's a starting list of irregular verbs: http://www2.gsu.edu/~wwwesl/egw/verbs.htm

Using the word processor search and replace method is bound to result in nonsense. You might as well re-write the whole thing.

Answer 2

Do you want to change your words from present tense to past tense or third person vs first person. You can do this with your normal word processor and use change and replace (if you are careful to make sure the changes make sense)

Here is an example of one kind of story converter:
http://www.keepwatch.com/storyconvert.htm