This is a superlative sentence with a monosyllabic adjective, so we need to change large to largest. Again, adding the intensifier by far doesn't have any effect on the adjective.

Well is an irregular adverb that becomes better in the comparative form. The word than indicates that this sentence is a comparative, so we should use better here.

The word than indicates that we're making a comparison here. Hard is a monosyllabic regular adverb (one syllable), which means that we can't use the word more. Like adjectives, monosyllabic regular adverbs add the suffix –er in their comparative form, so we need to use harder here.

Modifiers can be used in order to emphasize, specify, or clarify comparisons. As tea is an uncountable noun, we need to use much here, not many.

Two-syllable adjectives that end with –y usually change their spellings in the superlative form. The y becomes an i, so pretty becomes prettiest. Although two-syllable adjectives usually use most in the superlative, we shouldn't use it when the adjective changes form like this. Note that the already appears before world's, so we don't need to use it a second time.

The word than indicates that we're making a comparison here. Short is a monosyllabic regular adjective (one syllable), which means that we can't use the word more. Monosyllabic regular adjectives add the suffix –er in their comparative form. Note that adding the intensifier little makes no difference to the form of the adjective.

Far is an irregular adjective that becomes further or farther in the comparative form and the furthest or the farthest in the superlative form. The word than indicates that this sentence is a comparative, so we can use either further or farther here. For physical distance, it's generally better to use farther.

The superlative form of an adjective can be used in combination with the ordinal numerals to indicate the size of an object. Big is a monosyllabic regular adjective and so the superlative form is biggest. Note that the ordinal number third comes after the determiner the.

Two-syllable adjectives that end with –y usually change their spellings in the comparative form. The y becomes an i, so healthy becomes healthier. Although two-syllable adjectives usually use more in the comparative, we shouldn't use it when the adjective changes form like this. Note that the intensifier much doesn't affect the adjective.

The comparative form of an adjective can be used in combination with the cardinal numerals and times to compare measurable characteristics. Long is a monosyllabic regular adjective and so its comparative form is longer.

The word than indicates that we're making a comparison here. Often is a two-syllable regular adverb, which means that the adjective doesn't change form, and we need to use the word more. Note that the intensifier much doesn't change the form of the adjective: much more often than…

The word than indicates that this is a comparative again, so we can't use the most readable or as readable. Readable is a three-syllable adjective, so it doesn't change its form in the comparative. We should therefore use more readable.

Few is a regular monosyllabic adjective used instead of less with countable nouns. It changes to fewer in the comparative form and the fewest in the superlative form. The word than indicates that this sentence is a comparative, so we should use fewer here.

Less is an irregular adjective used with uncountable nouns. It stays as less in the comparative form and changes to the least in the superlative form. The word than indicates that this sentence is a comparative, so we should use less here.

The word than indicates that this is a comparative, so we can't use most difficult or as difficult. Difficult is a three-syllable adjective, so it doesn't change its form in the comparative. We should therefore use more difficult.

Good is an irregular adjective that becomes better in the comparative form and the best in the superlative form. The word than indicates that this sentence is a comparative, so we should use better here.