How many cards are (is) that?

Questions that start with how many often confuse writers because the verb must agree with the grammatical subject, not the noun inside the how many phrase. Both "How many are there?" and "How many is that?" can be correct - they have different subjects.

Read a quick diagnostic, plain rules for common patterns, plenty of wrong→right pairs, ready-to-use rewrites, and fast memory tricks you can apply immediately.

Quick answer: match the verb to the grammatical subject

If the grammatical subject is plural, use are. If the grammatical subject is singular (often a pointer like that/this or a single unit), use is. Test by replacing the how-many clause with that/they or by turning the question into a short statement.

Use are when the plural noun is the subject: How many books are there?
Use is when the subject is a singular pointer or unit: How many books is that?
Quick test: If "That is ..." sounds right, use is; if "They are ..." sounds right, use are.

Core explanation (the grammar test you need)

Many how-many questions hide the true subject. The verb must agree with that subject. Do one of these quick checks:

Replace method: Substitute "That is" or "They are." If "That is three cards" fits, use is; if "They are three books" fits, use are.
Rephrase method: Turn the question into a short statement (There are three books / That is three cards) and match the verb to that subject.
Look for demonstratives or units (that, this, the assignment, the box). When one of these is the grammatical subject, use is.

Example (pointing): How many cards is that? → That is three cards (singular subject → is).
Example (existential): How many books are there? → There are three books (plural subject → are).

Common patterns and quick rules

These short patterns cover most cases.

"How many X are there?" - X is the subject → use are.
"How many X is/are that/this?" - that/this often functions as the subject → use is.
"How many of the X are Y?" - the plural X controls the verb → use are.
"How many X does Y have?" - the auxiliary does/did matches Y (not is/are).

Work pattern: How many candidates are there? (are → candidates is subject)
School pattern: How many pages is that assignment? (is → assignment is subject)
Work pattern: How many of the team are available? (are → team members is plural)

Real usage: pointing vs. existential questions

Speakers and writers use two common senses: pointing at a single bundle (use is) and asking about how many exist (use are). Both are grammatical when context supports them.

Pointing/identifying a unit: use is - That is three boxes → How many boxes is that?
Existential/asking about quantity: use are - There are three boxes → How many boxes are there?
In formal writing, prefer the version that makes the subject unambiguous; when unclear, rewrite.

Work - Pointing: At a conference: How many people is that group? (pointing to the group → is)
Work - Inventory: How many items are in stock? (are → items is subject)
Casual: At dinner: How many pieces is that? (pointing to one serving → is)

Lots of wrong → right pairs (copyable fixes)

Common mistakes and their corrections. Copy the corrected sentence or use the note to see why the verb changes.

Casual - Wrong: How many cards are that?Casual -
Right: How many cards is that?
Work - Wrong: How many people is at the meeting?Work -
Right: How many people are at the meeting?
School - Wrong: How many pages are that assignment?School -
Right: How many pages is that assignment?
Casual - Wrong: How many slices are that pizza?Casual -
Right: How many slices is that pizza?
Work - Wrong: How many of the managers is attending the review?Work -
Right: How many of the managers are attending the review?
School - Wrong: How many points are this problem worth?School -
Right: How many points is this problem worth?
Work - Wrong: How many reports is on the desk?Work -
Right: How many reports are on the desk?
School - Wrong: How many students is in the class?School -
Right: How many students are in the class?
Casual - Wrong: How many photos is you take at the event?Casual -
Right: How many photos did you take at the event?
Casual - Wrong: How many books is in that pile?Casual -
Right: How many books are in that pile?
Casual - Wrong: How many of you is willing to volunteer?Casual -
Right: How many of you are willing to volunteer?

Try your own sentence

Test the whole sentence, not just the phrase. Context often makes the correct verb clear.

Rewrites you can use right away

If you're unsure, use one of these fixed frames to make the subject explicit or to rely on an auxiliary verb.

Make the plural noun the clear subject: "How many books are in that box?" instead of "How many books is that?"
Use an auxiliary when appropriate: "How many pages does the assignment have?" instead of "How many pages is that assignment?"
Turn the question into "There are ..." or "That is ..." in your head, then rewrite to match.

Casual - Rewrite:
Original: How many cards are that? → Fix: How many cards is that? or How many cards are there?
Work - Rewrite:
Original: How many people is at the meeting? → Fix: How many people are at the meeting? or How many people will attend the meeting?
School - Rewrite:
Original: How many pages are that assignment? → Fix: How many pages does the assignment have? or How many pages are in that assignment?
General rewrite: Instead of "How many books is that?" say "How many books are in that pile?"
Casual - Past auxiliary: Instead of "How many photos is you take?" say "How many photos did you take?"

Memory tricks and quick tests

Simple, reliable checks you can run in seconds until the pattern feels natural.

That / They test: Substitute "That is" or "They are." If "That is" fits, use is; if "They are" fits, use are.
Move-it test: Turn the question into a statement (There are X / That is X) and see which verb you need.
Auxiliary clue: If the question uses do/does/did, follow the auxiliary (How many pages does the report have?).

Mnemonic: Pointing to one thing → "That is" → use is.
Mnemonic: Asking how many exist → "There are" → use are.

Similar mistakes and related agreement traps

The same principle - find the head noun that controls the verb - fixes many other errors.

Collective nouns can be singular or plural by meaning: The team is ready (unit) vs The team are arguing (individuals).
Quantifiers vary: None can be singular or plural depending on meaning (None of the evidence is conclusive vs None of the pieces are missing).
Of-phrases: One of the students is late - "one" is singular, so use is.

Wrong: None of the evidence are conclusive.
Right: None of the evidence is conclusive.
School - Wrong: One of the students are late.School -
Right: One of the students is late.
Work - Usage: Collective: The team is meeting tomorrow. (treat team as a unit)

Hyphenation, spacing, and punctuation notes

Formatting doesn't change agreement, but clear punctuation and spacing make the subject easier to identify.

Don't leave a space before a question mark: "How many are there?" not "How many are there ?".
Keep modifiers next to the noun they modify: "How many students in total are registered?" is clearer than "How many students are, in total, registered?".
If you add parentheses or commas, ensure the noun that determines agreement remains obvious.

Spacing: Clear: How many people are coming?
School - Punctuation: Parenthetical: How many students, overall, are in the program?

FAQ

Should I use is or are after "how many"?

Find the grammatical subject. Use are when the subject is plural (How many people are here?). Use is when the subject is a singular pointer or unit (How many people is that group? → That group is the subject).

Is "How many cards is that?" correct?

Yes. The demonstrative that is the grammatical subject (singular), so is is correct. To ask about cards in general, use How many cards are there?

What if both forms sound okay in speech?

Context and emphasis decide. Pointing to a single bundle usually favors is; asking about existence favors are. In formal writing, choose the clearest form or rewrite to remove ambiguity.

How can I fix a sentence when I'm unsure?

Run the quick checklist: substitute that/they, rephrase as a statement (There are / That is), or apply a rewrite like "How many X are in Y?" or "How many X does Y have?"

Will grammar checkers catch these errors?

Many modern checkers flag subject-verb agreement and suggest rewrites. They help, but the quick tests above let you decide faster and edit more clearly.

Need a fast check?

When unsure, paste the sentence into a grammar checker or run the That/They test. With a few practice runs these checks become automatic and save rewriting time.