Predict the next word given an incomplete English Sentence.

Let me give you an example: How is it
The answer to this example can be: going?
Here is why: Given the partial English sentence 'How is it', the user has generated 'going?' as an output. This is an excellent example because 'How is it going?' is a common phrase in English Langauge.

OK. solve this:
old enough to be of some use in doing chores right off and young enough to be trained
Answer:
up