'Are’ needs to be replaced with ‘is’ to make the sentence contextually correct. This is because, ‘in subject verb agreement, we match the subject with the nearest verb or the verb with the nearest or the first subject. But the verb should be matched with the main subject of the sentence’. Here the main subject is ‘Ignorant’ which is singular and so is followed by a singular verb.

The phrase ‘could not be able’ needs to be replaced with ‘was not able’ to make the sentence correct. As the action has already taken place so use of modal is incorrect. Thus, the correct sentence would be, ‘She told her teacher that she was not able to attend the class the previous day because of heavy rains’.

Were’ needs to be replaced with ‘was’ to make the sentence grammatically correct. This is because,‘If the subjects are joined by as well as, with, along with, together with, and not, in addition to, but, besides, except, rather than, accompanied by, like, unlike, no less than, nothing but, led by, headed by, guided by, controlled by, governed by,etc..Then the verb will agree with the first subject’ Thus, the correct sentence would be, ‘Coleridge as well as Wordsworth was of the opinion that the opposite of poetry os not prose but science’.