Hi, I would like to develop a sentence recognition algorithm and i don't know how to implement it ....could you give me some ideas ..please ! Thanks a lot

It would be better if you gave a few examples of input and expected output. Otherwise we run the risk of talking about different things.

If your notion of what contitutes a "sentence" can be described by a context-free grammar, you can reduce that grammar to Chomsky Normal Form and then there is a simple recognition algorithm that runs in time O(n^3), where n is the number of words in your input.