NP -> Det N PPScombination rather than
NP -> Det N.
One of the typical problems here was getting a grammar that would build the trees for sentences, but not the correct ones. There were different cases, for example, the rule
NP => NP PPThe rule is correct to analyze sentences like "He saw a boy with red hair", but it will result in the analysis
[S [NP He] [VP saw [NP the man] [VP saw [NP [NP the wood] [PP with a saw]]]]]This get us very strange interpretation: "he saw someone sawing the wood which had a saw in it" or something like that, which is certainly not what we want to get. There may be multiple trees corresponding to the same sentence, but if you're asked to write a grammar that accounts for it, it should be able to produce only correct interpretations.
Another problem was that many people missed the clause "justify your grammar with examples". It is usually important to show that your grammar allows only correct analyses and disallows ungrammatical utterances, as well as that it can handle a range of sentences rather then some very specific type. I didn't penalize heavily for that this time if there were at least some examples provided, but this argument must be present in your future assignments. You can see my standard answers for what can be a reasonable example.
For grads only part, some people didn't notice that problem 4 in NLU had questions (a) and (b) and answered only 1 of them.
50.00
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65.00
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89.00