What two types of grammatical errors is nonnative speaker of English likely to make ?

Explanation:

While a wide variety of grammatical mistakes may be observed in the speech of non-native speakers, the types and frequencies of these mistakes are not random. Certain parts of speech, for example, have been shown to be especially problematic for Japanese learners of English [1]. Modeling these errors can potentially enhance the performance of computer-assisted language learning systems. This paper presents an automatic method to estimate an error model from a non-native English corpus, focusing on articles and prepositions. A fine-grained analysis is achieved by conditioning the errors on appropriate words in the context.

unrelated sentences to be eliminated?

i go to the store and buy some cheese,suddenly there was akward silence.   out of no where comes a ninja, and he takes an apple, and chokes the cashier, until he passes out.   the disapeared in a puff of smoke.   the cashier went to the doctor, and everything was fine again.   they all lived happily ever after without anymore ninjas.

the end

go to buy cheese= exposition

akaward silence= rising action

ninja chokes the cashier= climax

cashier goes to the doctor= falling action

they live happily ever after= resolution