<p>Can anyone explain to me the reasoning of why "introduction for" and "despite this" is grammatically incorrect (English was my second language)</p>
<p>The introduction for the new product line to consumers was delayed by technical setbacks not anticipated by the company's managers. No error.</p>
<p>The weather in Arizona and New Mexico is like some parts of California, but despite this similarity there are important climatic differences within these regions. No error.</p>
<p>I am not sure but I believe introduction for is incorrect because there is a common idiom, I believe it should be "introduction of"</p>
<p>The first error is idiomatic - "introduction of" is correct instead of "introduction for" .. that's just the way there is, there's no grammatical explanation.</p>
<p>You should check the answer to your second question. I think the error is around "like some parts of California"; it doesn't look like there's anything wrong with "despite this similarity.."</p>
<p>Ya it should be "like some parts of California" because you should be comparing the weather in Arizona and New Mexico's to California's not to parts in California.</p>