`Must′ expresses strong deduction or certainty based on evidence. `Might′ expresses possibility, `can′ with `be late′ is unlikely given `always punctual′, and `should′ expresses expectation or advice, not deduction.

`Give up′ is a phrasal verb meaning `stop doing something′. `Look into′ is correct phrasal verb form, not `look to′. `Wait for′ is prepositional verb, not phrasal verb in the same sense. `Improve′ is not used with `for′ in this phrasal context.

Past perfect (`had finished′) is used to show an action completed before another action in the past (`arrived′). Option 3 correctly places `had finished′ before `arrived′ to indicate sequence.

`In′ is used with parts of the day (afternoon, evening, morning). `On′ is used with days of the week and dates, `at′ with specific times. Options 1 and 3 use incorrect prepositions with days and time, option 2 is redundant with `year′.

A gerund is a verb form ending in `-ing′ that functions as a noun. `Swimming′ correctly acts as the subject of the sentence. `To swim′ is an infinitive.

The third conditional describes unreal past situations and their hypothetical past results, using `if + past perfect, would have + past participle′. `If I had studied hard, I would have passed′ fits this structure.

Zero conditional expresses general truths or habits, using `if + present simple, present simple′. `If it rains, we stay inside′ correctly follows this structure.

Comparative adjectives are used to compare two things. `More interesting′ is the correct comparative form for longer adjectives. `More taller′, `most tallest′ are double comparatives∕superlatives, `bigger than more your house′ is grammatically incorrect.

In reported speech, verb tenses usually shift back in time. `Am tired′ changes to `was tired′ when reported. Option 2 misses `that′ and tense shift, option 3 has incorrect word order in indirect question, option 1 is direct speech.

`Water′ is an uncountable noun, correctly used with `some′. `Sugar′, `advice′, and `knowledge′ are uncountable; `sugar′ is often made countable when referring to `teaspoons∕cubes of sugar′, `advice′ and `knowledge′ are always uncountable and do not pluralize.

`Few′ is a quantifier used with countable nouns in plural form. `Cars′ is countable and plural, making `few cars′ correct. `Much′ is for uncountable, `little′ implies insufficient quantity and may not fit with `friends′, `many′ is for countable but `water′ is uncountable.

`So…that′ correctly expresses cause and effect, showing result of intensity. `It was so hot that we went swimming′ clearly shows the heat caused the swimming. Option 1 is slightly redundant, option 2 reverses cause and effect, option 4 uses `because′ but misses `that′ to complete `so…that′ structure.

`If′ correctly introduces a condition, and `you will pass′ is the expected result. `Unless…so′ is redundant, `because…therefore′ is also redundant and slightly awkward, `if…but′ is contradictory.

`Wish + past simple′ (or `were′ for `be′) expresses regrets about present situations. `I wish I were taller′ correctly expresses a present regret. `Will be′ is future, `am′ is present fact, `had been′ is past regret.

`Under′ correctly indicates location beneath something. `On′ or `at′ table surface is better than `in′. `On′ is typically used for bus stops (surface), `in′ for vehicles.

Passive voice is formed with `be + past participle′. `Was baked′ is the correct passive form and `by my mother′ identifies the agent. Options 1, 2 and 4 have incorrect passive constructions.

`Might′ expresses possibility. `Must′ expresses certainty or strong obligation, `can′ expresses ability (and possibility in some contexts but not with `to′ which is incorrect), and `should′ expresses advice or expectation (and incorrectly used with `to′).

`An′ is used before vowel sounds. `Engineer′ starts with a vowel sound, making `an engineer′ correct. `Unicorn′ starts with a consonant sound ∕j∕, `honest′ with a vowel sound, and `sun′ requires `the′ as a unique entity, and `star′ needs `a′.

With `neither…nor′, the verb agrees with the noun closest to it. `Dogs′ is plural, but in `neither the cat nor the dogs *is* here′, the verb incorrectly agrees with `cat′. Corrected to `Neither the cat nor the dogs *are* here′. However, option 3 uses `is′ with `cat′, which is singular, making it correct in the given options.

The second conditional describes unreal present∕future situations and their hypothetical results, using `if + past simple, would + base verb′. `If I won, I would travel′ correctly follows this structure.

`Books′ is a countable noun correctly pluralized. `Milk′, `furniture′, and `sheep′ are either uncountable or have irregular plural forms (`sheep′ is the same in singular and plural). Option 4 is the only correct plural form of a countable noun.

`Where′ is correctly used as a relative pronoun to introduce a clause specifying location. `Who′ and `which′ are incorrect for objects like `book′ and `woman′ in these contexts; `that′ is acceptable for restrictive clauses, but `where′ is more precise for location.

`Although′ correctly introduces a contrasting idea. `Because…so′ is redundant. `Although…but′ is also redundant. `Despite′ requires a noun phrase or gerund, not a clause starting with `it was′.

`To learn′ (infinitive) is correctly used as the subject and expresses purpose effectively. `For learning′ is less common as subject. Option 3 is grammatically incomplete. Option 4 uses `because improving′ which is not standard.

Question tags are short questions at the end of statements, formed with auxiliary verb and pronoun, reversing polarity of statement. All options correctly form question tags: positive statement with negative tag (option 1), negative statement with positive tag (option 2), and modal verb with reversed tag (option 3).

Reflexive pronouns are used when the object of a verb is the same as the subject. `Herself′ correctly reflects back to `She′ as the recipient of the action `bought′.

The present perfect continuous is used for actions continuing up to now, but `know′ is a stative verb, which doesn′t typically use continuous tenses. Therefore, present perfect simple `have known′ is correct for states lasting until now.

`Would rather + base verb + than + base verb′ is the correct structure for expressing preference. `I would rather stay home than go out′ follows this structure correctly. Other options have incorrect verb forms after `would rather′ and `than′.

`Used to + base verb′ describes past habits or states that are no longer true. `Used to play′ correctly conveys a past habit. `Be used to + gerund′ means `be accustomed to′, `used to playing′ is grammatically incorrect, and `use to played′ has incorrect verb form.

Superlative adjectives are used to compare three or more things, indicating the highest degree. `The highest′ is the correct superlative form, used with `the′. Options 1, 2, and 4 have incorrect superlative constructions.