Certain nouns being a singular form represent plurality and therefore, take a plural verb in a sentence. Certain nouns take the plural verb because of their plural form.
When a noun denoting weight, number, money, length, or measure is following a number, the noun form does not change as long as another noun or pronoun follows it.
Sentences are always opposite to question tags, for example, if the question tag is positive then the sentence is negative and vice versa.
‘Though’ is always followed by ‘yet’ in a sentence and not by ‘but’. 'Not’ is never used with ‘unless’ as ‘unless’ expresses a condition that is always used in the negative sense.
Check for the correct usage of proper nouns and if they are written in CAPITAL letters, for eg., Neeta Arora, the Great Wall of China etc.
Always remember that generally, if one part of a sentence is in the past tense, the other half should also be in the past tense.
Check for the correct usage of nouns/pronouns/adjectives and adverbs in a sentence. Also, check if proper conjunctions and prepositions have been used.