# Should I use CONTAINS or CONTAIN?

An example of a miniature Sudoku puzzle is:

Notice that it consists of four rows, four columns, and four 2 x 2 boxes.

I was thinking of using the following wording for the instructions:

Fill each empty square with a number so that every row, every column, and every 2 x 2 box contains all the numbers 1, 2, 3 and 4 each exactly once.

I am uncertain whether my instructions should use the word CONTAINS or CONTAIN. Which is better and why? Any other help in improving the instructions would be appreciated.

"contains". You are not compounding the singular subjects "every row" (etc) to make a plural subject, you are giving three parallel singular subjects.

• Your answer would have been be correct if the 3 items were linked by an "or" instead of the "and". But, considering the "and", I don't share your opinion because the subject of the verb is row+column+box, giving the plural "contain" for the verb. Jun 17, 2023 at 0:35
• @Graffito — The repeated "every" belies that conclusion. Some compromise is needed in language. "Every contain" is just never going to work in English. Jun 17, 2023 at 3:18
• @Graffito If you feel this is incorrect please do write you own answer. Jun 17, 2023 at 4:27
• @ralph.m & JamesK : My comment was just an opinion, but after searching some supporting text to sustain this feeling, I wrote an answer. Jun 17, 2023 at 9:47
• @JamesK could you provide more information due to the new answer? I really want to know what the right answer is. Jun 19, 2023 at 22:43

According to this Washington university document related to verb-subject agreement in case of compounds subjects :

Subjects joined by "and" are nearly always plural.
Example => Ben and Nicholas like to play soccer.

Exception: If the parts of the subject are considered a unit, you may treat the subject as singular.
Example => Crackers and cheese is my favorite snack.

In the OP sentence, the names composing compound subject are linked by an "and". Thus, the verb should use the the plural, i.e. "contain".

It may sound weird to some people to use a plural after every, because "every" in itself is singular, e.g. "every man has certain basic human rights".
But, between "every man and every woman has certain basic human rights" and "every man and every woman have certain basic human rights", I will choose the second option.

• I'm not an expert, but I would also use the 'contain', considering that we are talking about the plural. Jun 19, 2023 at 22:40

It's a simple matter of plural vs singular. You would say that a singular box contains things, while plural boxes contain things:

• The box contains...
• The boxes contain...

Although you are speaking about many boxes, we use the words "each" or "every" to refer to individual things in a group. So, although all the boxes contain numbers, each box contains numbers.