Break it down word by word:

(Its/It's): "It is" fits, so It's ✅ (contraction of "it is")

(their/there/they're): "they are" fits, so they're ✅ (contraction of "they are")

(whose/who's): "who is" fits, so who's ✅ (contraction of "who is")

Complete sentence: "It's they're responsibility to fix who's mistake?"

Wait — let me re-read. If the sentence means "It is their responsibility to fix whose mistake?":

It's (it is) their (possessive, belonging to them) responsibility to fix whose (possessive, belonging to whom) mistake?

Key rules:

• Its = possessive / It's = it is
• Their = possessive / They're = they are / There = location
• Whose = possessive / Who's = who is

Answer: "It's their responsibility to fix whose mistake?"

SAT Tip: Expand the contraction. If "it is" works → "it's." If not → "its."

Error: Verb tense inconsistency

"Finished" → past tense (correct, matches "last week") "Will submit" → future tense BUT "yesterday" is in the past

Fix: "The team finished the project last week and submitted it yesterday." ✅

Another possible fix (if the action hasn't happened): "The team finished the project last week and will submit it tomorrow." ✅

Rule: Verb tenses must be logically consistent with time markers.

Past time markers: yesterday, last week, in 2020, previously Present: now, currently, today, at this moment Future: tomorrow, next week, soon, eventually

Answer: Change "will submit" to "submitted" (or change "yesterday" to "tomorrow").

SAT Strategy: When you see verb tense answer choices, look for time clue words in the sentence to determine the correct tense.

Error 1: Subject-verb agreement "The artist... have recently opened" → Subject is "artist" (singular) → should be "has"

Error 2: Pronoun case (subtle) "who many critics consider" → "who" is the OBJECT of "consider" (critics consider ___) → should be "whom"

Corrected: "The artist, whom many critics consider to be one of the greatest painters of the century, has recently opened a new exhibition." ✅

Why this is tricky:

• The long clause between commas makes you lose track of the subject ("artist")
• "Who" vs. "whom" depends on function within the clause: "critics consider [whom]"

Answer: Change "who" to "whom" and "have" to "has."

SAT Pattern: Long sentences with intervening clauses are designed to make you forget the original subject.

This tests dangling modifiers:

"Having completed the experiment" must modify the noun that immediately follows it — whoever completed the experiment.

(A) "the results surprised" → Did the RESULTS complete the experiment? No! ❌ (Dangling modifier)

(B) "the researchers were surprised" → Did the RESEARCHERS complete the experiment? Yes! ✅ (Correctly attached)

(C) "it was surprising" → Did "IT" complete the experiment? No! ❌ (Dangling modifier)

Answer: (B)

Rule: A participial phrase at the beginning of a sentence MUST modify the subject that follows the comma.

Pattern to memorize: "[Participial phrase], [DOER OF THE ACTION] + [rest of sentence]."

"Running down the street, I tripped." ✅ "Running down the street, the sidewalk tripped me." ❌ (Sidewalks don't run)