Parallelism, Modifier, Repetition and Redundancy

 Forbade is already negative. So, 'not' is redundant.

For proper parallel structure, the comparison should be 'by sea' vs 'by land'. Saying 'than land' breaks the grammatical pattern established in the first part. The correct phrase should be 'Transporting goods by sea is cheaper than by land'.

The sentence has a pronoun reference error. 'The ship' is singular, but 'they' is plural. It should be 'it sailed in' to maintain subject-verb agreement. The correct phrase is 'The ship was caught in a storm as it sailed in along the coast of Japan'.

The subject 'Insulation' is singular, so it needs a singular verb. 'Protect' is plural/infinitive form; it should be 'protects' (singular form) to agree with 'Insulation'. Additionally, the list should use 'protects... are' where each item has its appropriate verb form.

Instead of newspaper, it should be newspapers.

The phrase 'of a character of history' is grammatically awkward and breaks the parallel structure. The correct parallel form should be 'historical' (adjective) to match 'religious' and 'ceremonial'. The correct phrase is 'Paintings of a religious, ceremonial, or historical character' - or 'of historical character' without the redundant 'of'.

Wind pushes sand up the side of a dune (intransitive), not upward one side (transitive). 'Upward one side' suggests pushing sand to a location, but the context describes the sand's path of movement. 'Up the side' correctly shows the directional movement along the dune's surface.

no error

 instead of 'slenderness' it should be 'slender'

 Replace 'them' with 'whom'. It is a subordinate clause and use of 'them' would make it an independent clause, making the sentence incorrect.

After 'refused the request that', the subjunctive mood is required for the subordinate clause. 'Be waived' is the correct subjunctive form, not 'shall be waived' (future indicative) or 'should be waived' (suggestion). The subjunctive expresses necessity or recommendation after verbs like request, insist, propose.

Comparisons must be parallel. 'Sudha's hair' must be compared to 'Richa's hair' (possessive), not just 'Richa' (person). 'Hair is lengthier' is correct because hair (as a collective noun) takes a singular verb when referring to the overall length or mass of hair.

The parallel structure requires 'to pursue' (infinitive) to match 'to make' (infinitive). 'Matured' is incorrect - 'mature' is the adjective form. 'Sufficiently mature' is correct word order (adverb + adjective). 'Pursue his goals' is active and direct.

The sentence structure requires 'being' to match the earlier phrase 'just being a guard'. 'Apart from being the perceived perpetrator' maintains parallelism. 'Perceived perpetrator' is a noun phrase that needs 'being' to function as a complement to 'apart from'.

'Scarcely' is already negative, so adding 'nothing' creates a double negative. 'Scarcely anything' means 'almost nothing', which is the intended meaning. 'Next to nothing' is also correct but 'scarcely anything' is the most direct correction.

The subject of the second clause should refer back to 'mathematical theories' (they), not 'our comprehension'. The theories may have enhanced comprehension - comprehension doesn't enhance itself. Active voice 'they may have enhanced' is clearer than passive.

'Not hardly' is a double negative. 'Hardly' is already negative, so adding 'not' is incorrect. When a negative adverb like 'hardly' starts a sentence for emphasis, subject-auxiliary inversion is required: 'Hardly did anyone protest'. 'Hardly anyone protested' is grammatically correct but lacks the formal emphasis the inverted structure provides.

After 'essential that', the subjunctive mood is required. 'Be filed' is the correct subjunctive form, not 'are filed' (indicative). The subjunctive expresses necessity or urgency after adjectives like essential, necessary, important, critical.

After 'recommended', the subjunctive mood 'should study' is correct and natural. 'Study' (bare subjunctive) is also correct but less common. 'Studies' (indicative) and 'studied' (past) are wrong. 'Should study' clearly expresses the recommendation.