The two errors are missing the verb "will" after the pronoun "I" at the beginning of the sentence, and there is missing the article "a", after the word "watermelon".
The correct phrase would be:
<em>"In today’s blog post, I </em><em>will </em><em>teach you how to make </em><em>a </em><em>watermelon salad with feta and mint! With less than five ingredients, it’s a feast for the eyes and the palette."</em>
Answer: Middle English language, the vernacular spoken and written in England from about 1100 to about 1500, the descendant of the Old English language and the ancestor of Modern English. ... During this period the basic lines of inflection as they appear in Modern English were first established.