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Serenity Carr, Assistant Editor
When to Use "Don't" and When to Use "Doesn't"
Thursday September 21st 2017
Question
When should I use don't and when should I use doesn't? — Learners Everywhere
Answer

Many users have written to us asking whether don't or doesn’t is correct in a particular sentence, or asking what the difference between don't and doesn’t is.

 

Both don’t and doesn’t are contractions using the verb do and the word not. It's easier to see which one is the correct choice if you expand the contractions: don’t is a contraction of "do not" and doesn't is a contraction of "does not." We know that a verb with a third person singular subject gets an -s or -es on the end in the simple present tense. This is true for all regular verbs.

 

The verb call has an -s when it has a third person singular subject:

  singular plural
1st person I call we call
2nd person 
you call you (all) call
3rd person he/she/it call
they call

 

 

The verb miss has an -es when it has a third person singular subject:

  singular plural
1st person I miss we miss
2nd person  you miss you (all) miss
3rd person he/she/it misses  they miss

 

 

With a third person singular subject, the verb do becomes does:

  singular plural
1st person I do we do
2nd person  you do you (all) do
3rd person he/she/it does  they do

 

 

So then, in the contractions with the word not, don't becomes doesn't with a third person singular subject:

  singular plural
1st person I don't [=I do not] we don't [=we do not]
2nd person

you don't [=you do not]

you (all) don't [=you (all) do not]

3rd person

he/she/it doesn't [=he/she/it does not] 

they don't [=they do not]

 

 

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