Lesson 27 of 41 in the Test Ninjas TOEFL course: Build a Sentence, Writing. Long replies often join two clauses: the one who…, exactly what I needed, if the roads are closed, so that she could rest.
Test Ninjas Research · Updated October 1, 2026
Lesson at a glance
Detail
This lesson
Module
Build a Sentence (Writing)
English focus
Relative clauses (who, whom, that, which, and what meaning the thing that); real and imagined conditions (will / would, if it weren't for, Would it be okay if I + past); purpose clauses with so that + can/could
Task skill
Building longer two-clause sentences and recognizing the tile that doesn't belong, usually the near-twin of a needed tile (who/whom, what/which, isn't/aren't, shares/shared)
Time
About 55 minutes
Access
Included in the TOEFL plan
What this lesson teaches
Long replies often join two clauses: the one who…, exactly what I needed, if the roads are closed, so that she could rest.
The link word at the join decides what the second clause must look like: which word starts it, what tense its verb takes and what that verb agrees with.
In Build a Sentence, the extra tile in these replies is usually a near-twin of a tile you need (who/whom, what/which, is/are, open/opened), so you need to know why one twin works and the other doesn't.
By the end of the lesson, you can
Join a describing clause with who (people), which (things) or that (both); use who when it's the subject of the clause and whom only as a formal object; use what for “the thing that” when no noun comes before it; and make the verb inside the clause agree with the noun it describes.
Build real conditions (What will you do if… + present), imagined or polite ones (would + if + past: if I lived, if it weren't for + noun, Would it be all right if I sat…), and purpose clauses with so that + subject + can/could.
In Build a Sentence, find where the second clause starts, choose its link word, keep statement order and the right tense inside it, and leave the near-twin (whom, which, isn't, opens) as the extra tile.
What’s inside
Around the 3 teaching cycles below, the lesson opens with a quick check and closes with applied practice, a Check and a debrief. How every course lesson is built.
Teaching cycles in lesson 27
Cycle
Focus
What it teaches
Drills
Cycle 1
English
Relative clauses: who, that, which and what
7
Cycle 2
English
Conditions and purposes: if, if it weren't for, so that
7
Cycle 3
Task skill
Long sentences and the extra tile
7
Word bank
The 10 words and phrases this lesson teaches. They come from the real course questions you practice on in the Apply step, so you meet each one again in context.
shift noun
a set period of work time, such as a day or night shift
Nurses on the night shift start at ten and finish at six.
Goes with:
work the night shift
Word family:
shift (verb): move; night shift / day shift (noun)
organized adjective
good at planning things and keeping them in order
Dario keeps a color-coded calendar; he's the most organized person I know.
Goes with:
well organized
Word family:
organize (verb); organization (noun); organizer (noun)
a room to myself noun phrase
used by only me, with nobody else there
My flatmates were away, so I had the kitchen to myself all weekend.
Goes with:
have the place to yourself
Word family:
have something to yourself; to herself / to ourselves
single noun
a room for one person, for example in a dorm or hotel
The guesthouse has four doubles and two singles, and a single costs a little less.
Goes with:
book a single
Word family:
single (adjective): one; double (noun); a single room
language exchange noun
an arrangement where two people teach each other their languages
Wen teaches Farid Mandarin, and Farid teaches Wen Arabic: it's a language exchange.
Goes with:
join a language exchange
Word family:
exchange (verb); exchange student (noun)
outside of class prepositional phrase
away from lessons, in your free time
Our study group also meets outside of class, at the library on Sundays.
Goes with:
outside of class
Word family:
outside (of) work / school; in class (the opposite)
seem verb
to appear to be; to give an impression
Your new neighbor seems to know everyone on the street.
Goes with:
seem tired / seem to know
Word family:
seemingly (adverb); it seems that…
would love to phrase
a warm way to say you really want to do something
“Want to join us for dinner on Friday?” “I'd love to!”
Goes with:
I'd love to + base verb
Word family:
I'd love to (short answer); would like to
left adjective
still there after the rest has been used
There's no milk left, so I'll buy some on the way home.
Goes with:
there are no tickets left
Word family:
leave (verb); leftovers (noun)
practice verb
to do something again and again to get better at it
Kofi practices speaking in front of a mirror before every presentation.
Goes with:
practice + -ing
Word family:
practice (noun); practical (adjective); UK spelling of the verb: practise
The takeaway: In a long sentence, find where the second clause starts, choose its link word from what comes before it, and let the first clause set the tense; the extra tile is usually the twin you didn't need.
In the full course
Relative clauses, conditionals and the extra tile is part of the full TOEFL course
Unlock all 41 lessons with the TOEFL plan, or try one of the free lessons first.
✓All 3 teaching cycles of this lesson, with 21 drills and feedback on every answer
✓The 10-word bank, each word with a recall drill
✓A walk-through, guided practice and a Check on Build a Sentence