SAT READING & WRITING · RACHEL · CLASS 07 · OCTOBER 17

Class Summary

Class Recap

Punctuation: The Comma, Unit 2: what a clause is, independent and dependent clauses, the three kinds of joining words, compound and complex sentences, the comma rules for a dependent clause (C4–C6), and Questions 4–5.
Grammar: Subject–Verb Agreement, Finding the Subject (A1–A3): the verb matches the simple subject, not the nearest noun, and words between the subject and the verb do not change its number. Questions 1–2.
Reading: Inferences, Question 2 (Maya marketplaces): read the direction words first, find the new idea, then keep only the choices on that topic.
Homework: 10 subject–verb agreement questions and 10 comma questions, plus last week’s three sets.

Same level or not? FANBOYS join two clauses of the same weight (IC + IC). A subordinating conjunction makes its clause lean on the main clause (DC + IC). That is why although … , but … is wrong: although has already made the first clause a DC, and but can only join two ICs.
The rule is about structure, not about one word. In Question 5 you said there can’t be a comma before when. The right reason is different: the when clause came last and told when, so it took no comma (C5). A comma can appear before when in other structures, for example when but joins two ICs and the second IC opens with a when clause.

✓ The test seemed easy, but when the timer started, I panicked. (IC, but [DC, IC])
✓ I panicked when the timer started. (DC last, telling when: no comma)
✗ I panicked, when the timer started.

A long tail with no finite verb is not a clause. In Question 4 you felt the two parts after the blank were equally important. Test each part for a finite verb: consuming antioxidants can neutralize harmful effects has one, so it is the IC. reducing the risk of heart disease … has none: it is an -ing phrase that adds the result of the IC. that are linked to oxidative stress is a describing clause inside that phrase. Neither changes the punctuation at the blank.

✓ The new filter removes most of the dust, reducing the need for cleaning. (IC + -ing phrase: one sentence)
✓ The new filter removes most of the dust, and it reduces the need for cleaning. (IC, and IC)
✗ The new filter removes most of the dust, it reduces the need for cleaning. (comma splice)

For your own writing: compound → complex. When a draft joins two ideas with and or so, try making one of them a DC. It shows which idea matters more and how the two are linked.

Compound (IC, FANBOYS IC)	Complex (DC, IC)
The data were incomplete, so the team repeated the trial.	Because the data were incomplete, the team repeated the trial.
The first result was promising, but the team was cautious.	Although the first result was promising, the team was cautious.
The pressure rose, and the alarm sounded.	When the pressure rose, the alarm sounded.

Phrase or clause in the middle? Your question in class was whether built and collected are past-tense verbs of the sentence. Ask whether the middle part has its own subject.
built by two rival companies: no subject of its own → a participial phrase. Built has no tense; it describes the bridge (the bridge was built by them).
the technician collected last week: its own subject, technician → a describing clause with that left out (the samples [that] the technician collected). Collected is the verb of that small clause only.
Either way, the middle part describes the noun before it and does not decide the main verb. The main verb matches the main subject.

Sentence	Middle part	Main subject → verb
The bridge, built by companies, carries traffic.	participial phrase, extra (in commas)	bridge → carries
The bridge built by companies carries traffic.	participial phrase, tells which bridge	bridge → carries
The bridge the companies built carries traffic.	clause, that left out	bridge → carries
The samples the technician collected show no change.	clause, that left out	samples → show

Commas or no commas. With two commas the middle part is extra: delete it and the sentence still says the same thing. Without commas it tells which one. Neither kind ever goes between the subject and its verb on its own: never one comma between a subject and its verb.

✗ The samples the technician collected last week, show no change.
✓ The samples the technician collected last week show no change.
✓ The letters that the museum bought are kept in Dublin. (clause with that kept)
✓ The letters the museum bought are kept in Dublin. (the same clause, that left out)

First read only the direction words. In Question 2: used to believe (an old view, now seen as flawed) → One reason for this belief (why they held it) → typically … because (the new idea: how marketplaces really arise) → seriously underestimated … and thus assumed that (the blank is what the scholars wrongly concluded).
Then read the new-idea sentence closely. Marketplaces appear when groups trade resources they control for resources they do not control.
Keep only the choices on that topic (marketplaces: A and C), then check each for new information. You found the trap in A yourself: the text never mentions traders from outside. C stays inside the text: the scholars, seeing no variety, assumed there was nothing different to trade.

Clauses: Before choosing, mark each finite verb with its subject. A subordinating conjunction makes a DC. DC first: comma. DC last (time, reason, condition): no comma. whereas: comma before.
Agreement: Cross out of-phrases, anything between commas or dashes, and describing phrases or clauses. Then match the verb to the simple subject. Settle singular or plural first, then the tense.
Inferences: Direction words first, then the new-idea sentence, then only the choices on that topic.
Homework: Last week’s Grammar 20, Punctuation 10 and Inferences 10, then this week’s Agreement 10 and Comma 10. Mark the clauses or cross out the middle words before you look at the choices.