Use to or Used to: Know the Differences and Rules

Both used to and use to are idiomatic English phrases. Depending on their purpose in a sentence, they can establish an action that no longer occurs or state that the speaker is accustomed to something. Their use changes their part of speech.

The most common mix-up between used to and use to occurs when describing the feeling of being accustomed to something, or “used to” it. Here are some examples of used to as an adjective. Notice that each of these sentences also includes a form of the helping verb to be (is, wasn’t, are).

• She’s use to disappointment. (Incorrect)
  She’s used to disappointment. (Correct)
• Carl wasn’t use to sleeping with the window open. (Incorrect)
  Carl wasn’t used to sleeping with the window open. (Correct)
• The students are use to staying inside when it’s raining. (Incorrect)
  The students are used to staying inside when it’s raining. (Correct)

Using used to as an adjective is clear cut – always used to, never use to. You’ll noticed that used to is followed by a noun in these examples. “Sleeping” and “staying” are gerunds, words that are formed from verbs but function as nouns.

Someone can be “used to” to a condition or situation, but they are never “use to” it. But, that doesn’t mean there’s no place for use to in a sentence.

Both used to and use to are commonly used as modal verbs, which are a type of helping verb that establishes a sentence’s mood. They both combine with an infinitive (to + verb) to explain that an action no longer happens. Some used to examples include:

• She used to swim every morning.
• Henry used to want to be a firefighter.
• The school used to have fourteen teachers.

These sentences all use used to as past-tense verbs. If you remove used to, the sentences would be in the present tense. They would also have subject-verb disagreement.

Did you used to or use to ride your bike to school? The only correct time to write use to is when you also use the words did or didn’t. These sentences are meant to clarify past behavior. Some examples of correct uses of use to include:

• Did you use to go to Jefferson High School?
• Didn’t your dad use to play bass guitar?
• I didn’t use to enjoy green tea, but now I do.

Did and didn’t are already in the past tense form, so you don’t need to add the d to use. A rare exception to this rule is the uncommon contraction usedn’t to, which means “didn’t use to.” However, you’re not likely to use or see the word American English.

So why is there so much confusion around these phrases? The letter d makes it easy to tell use to and used to apart in writing. But when speaking, use to and used to are almost interchangeable. The reason is phonetic: they sound almost identical to a listener.

Read these sentences aloud:

• I used to go fishing with my dad.
• I use to go fishing with my dad.

Did you hear a difference? If not, you’re not the only one. There are a few reasons why your ear can’t tell them apart.

The word use has different sounds depending on its context and purpose. When it’s used as a noun, it sounds one way; when it’s in a verb form, it sounds another way. Here are some examples of how use changes sounds.

• The verb use has a z sound when it means “to put into action.”
  Example: Use these scissors to open the box.
• It has an s in the noun form, which means “the intended purpose of an item.”
  Example: Put these scissors to good use.
• It also has an s sound when it’s used as a verb to mean “to no longer complete an action or participate in an activity.”
  Example: Kerry used to cut boxes open with a knife.

When describing an activity you no longer do, you use the third pronunciation. Both use to and used to are pronounced with an s sound. Even though the past tense used has a z sound, it changes to an s sound in this context.

The d in used is another reason why it’s hard to tell these phrases apart. It blends with the t in to make use to and used to sound very similar. Because they both use the soft s sound as well, it’s hard to tell which phrase a speaker is actually saying.

The audible similarities between use to and used to sometimes make their way into writing. Even though you can’t hear the difference, not knowing the correct usage rules can result in errors like “I use to skateboard” or “Did you used to live next door to me?” As in every grammar rule, knowing the basics is the best way to avoid basic mistakes.

If you’ve got additional grammar questions, check out more resources on the differences between common words. Learn when to use in versus into in a sentence. You can also decide whether you should follow the a versus an guidelines every time, or whether there are exceptions to the rule.