Lesson 24 of 41 in the Test Ninjas TOEFL course: Build a Sentence, Writing. A direct question puts a helper verb, the auxiliary, in front of the subject: Are you staying…?Has the bus left?Did Olu visit…?
Test Ninjas Research · Updated October 1, 2026
Lesson at a glance
Detail
This lesson
Module
Build a Sentence (Writing)
English focus
Direct question formation with do/be/have and modals; the verb form each auxiliary demands; tense and aspect in questions; tag questions; negative inversion; How come with statement order
Task skill
Building the frame first (auxiliary + subject + main verb), then filling the rest, and rejecting the wrong auxiliary or verb form as the extra tile
Time
About 50 minutes
Access
Included in the TOEFL plan
What this lesson teaches
A direct question puts a helper verb, the auxiliary, in front of the subject: Are you staying…?Has the bus left?Did Olu visit…?
Which helper you need depends on the main verb:
- a form of be for an ‑ing verb
- have/has/had for a perfect (a passive uses be: Were the tickets sold?)
- do/does/did or a modal for a base verb
In Build a Sentence the tiles often include two helpers, or two forms of the same verb, and one of them is the extra tile.
This lesson teaches you to let the main verb choose its helper, to build auxiliary + subject + main verb before anything else, and to handle three patterns that play with the order: tag questions, negative openings such as Never and Rarely, and How come.
By the end of the lesson, you can
Form direct yes/no and wh- questions with the right auxiliary for the tense (do/does/did + base verb, be + ‑ing, have/has/had + past participle in a perfect, modal + base verb), placed before the subject, with the main verb in the form that auxiliary demands; and know the exceptions: be as a main verb, main-verb have, and subject questions.
Match a tag question to the auxiliary and tense of its statement; put the auxiliary before the subject after a negative opening (Not once, Never, Rarely, Only after…); and keep How come in statement order.
In Build a Sentence, read the fixed words to find which auxiliary the sentence needs, build auxiliary + subject + main verb first, then add the rest, and leave the wrong auxiliary or the wrong verb form in the bank 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 24
Cycle
Focus
What it teaches
Drills
Cycle 1
English
Auxiliary, subject, main verb
7
Cycle 2
English
Tense in the auxiliary: perfect forms, tags and negative openings
7
Cycle 3
Task skill
Frame first, then fill
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.
email verb
to send someone a message by email
The department emailed me the new room number this morning.
Goes with:
email someone (no to); email someone a file
Word family:
email (noun): an email; emailed (past)
hold verb
to organize an event and make it happen
The student union holds an election for new officers every March.
Goes with:
hold an event / a meeting / an election
Word family:
held (past, past participle); holding (‑ing)
move indoors verb phrase
to take something from outside to inside a building
The café moves its outdoor tables indoors every evening at closing time.
Goes with:
move something indoors (no the); get moved indoors
Word family:
indoor (adjective): an indoor pool; outdoors / outdoor (opposites)
finals week noun phrase
the week of final exams at the end of a term
The dining hall stays open until 2 a.m. during finals week.
Goes with:
during finals week
Word family:
finals (noun): the final exams; final (adjective)
sign up phrasal verb
to add your name to a list to join something
I signed up for a pottery class on Wednesday evenings.
Goes with:
sign up for a class / a trip / a workshop
Word family:
sign-up (noun): the sign-up sheet; signed up (past)
reschedule verb
to change the time or date of a planned event
The dentist rescheduled my appointment for next Tuesday.
Goes with:
reschedule a meeting for Thursday
Word family:
schedule (noun and verb); rescheduled (past)
switch verb
to change from one thing to another
Ines switched seats so she could see the board better.
Goes with:
switch from A to B; switch seats / schools
Word family:
switch (noun): a switch; switched (past)
by the time conjunction
before a certain moment; not later than when
By the time we got to the station, the last train had left.
Goes with:
by the time + a clause
Word family:
by then (adverb phrase); until (a different meaning)
because of preposition
as a result of; caused by
The train was twenty minutes late because of a signal problem.
Goes with:
because of + a noun: because of the noise
Word family:
because (conjunction) + a clause; due to (formal)
upstairs adverb
on a higher floor of a building
The seminar rooms are upstairs, next to the printing office.
Goes with:
go / study / live upstairs (no to, no the)
Word family:
downstairs (opposite); upstairs (adjective): the upstairs rooms
The takeaway: Let the main verb choose its helper, put the helper before the subject, and test the leftover tile: it is usually a helper or a verb form you didn’t need, but not every reply has one.
In the full course
Questions and auxiliaries 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