Suppose vs. Supposed: What’s the Difference?

There are countless words in the English language that confuse writers on a daily basis. Today’s words, suppose vs. supposed, are no different.

How exactly do you use suppose and supposed, and what are their key differences? Do they have different meanings? Do they function differently?

What is the Difference Between Suppose and Supposed?

In today’s post, I want to address all of these questions. I will discuss the different functions of these two words, their definitions, and a few tricks you can use to remember their differences in the future.

After reading this post, you won’t ever again question your own usage, “Should I use suppose or supposed?”

When to Use Suppose

help with english grammar and homophonesWhat does suppose mean? “Suppose” can be used as a verb to mean to assume to be true or real for the sake of argument or explanation.

  • I suppose I could afford that if I had to.
  • Suppose you win the lottery, what would you buy?
  • For the sake of debate, she supposed the opponent was telling the truth.

Another meaning is to assume that something is the case on the basis of evidence or probability but without certain proof.

  • I’m not sure, but I suppose I arrived at 11.
  • Scientists supposed that dinosaurs lived in swamp regions.
  • I suppose you could be right, but I haven’t done the research.

Phrases That Use Suppose

A popular phrase that uses the word suppose is “I suppose so.” This is used to express hesitant or reluctant agreement. For example,

-Are you ready to go?

-I suppose so, although I wanted to relax this weekend.

-Are you going to the party tonight?

-I suppose so.

When to Use Supposed

supposed to versus suppose toWhat does supposed mean? Supposed vs. suppose can be confusing because the past tense of suppose is supposed, which is the same spelling of the adjective supposed. This leads to confusion between the verb and the adjective uses.

As we discussed above, suppose has a variety of meanings, assume something to be the case, used to make a reluctant admission, etc. Those same meanings can be used in either the present tense (I/you suppose, he/she supposes) or the past tense (I/you/he supposed).

  • She supposed her partners were right, but now what?
  • He supposed the customer to be 19 years of age.

The primary use of supposed, however, is the adjectival form, which has two primary meanings.

The first meaning of the adjective supposed (pronounced suh-po-zed) is generally assumed or presumed to be case, but not necessarily so.

  • Your supposed friend might be your primary enemy.
  • After the initial investigation, the supposed criminal was shown to be innocent.
  • He admired his supposed business acumen.

As you can clearly see, supposed is acting as an adjective in this form. In every sentence above, it precedes a noun. That’s a classic indicator that something is acting as an adjective.

The second meaning of the adjective supposed (pronounced suh-post) is to indicate something that is intended, required, permitted, expected. For example,

  • This medication is supposed to relieve minor headaches. (Intended)
  • Soldiers are supposed to follow the orders of their commanders. (Required)
  • We are not supposed to pass notes in class. (Permitted)
  • We are supposed to go the party. (Expected)

This second meaning of supposed is the most commonly used form by far.

Suppose to vs. Supposed to

supposed to or suppose toIs it suppose to or supposed to? As discussed in the section above, when you wish to say you are required or obliged to do something, you want to use supposed to, not suppose to.

  • I’m not supposed to eat cookies before dinner. (Correct)
  • I’m not suppose to eat cookies before dinner. (Wrong)

Using suppose to when you mean supposed to is an increasingly frequent error, but one that is widely shunned.

Tricks to Remember the Difference

Are you on information overload? No worries. Here’s a good trick to remember when to use suppose or supposed.

Suppose is used a verb, while supposed is used, primarily, as an adjective. To remember when to use them, pair the shorter word with the shorter grammar term.

In other words, suppose and verb are shorter than supposed and adjective.

Supposed also has a “D” at the end of it, which can signal its primary use as an Adjective, which also has a “D” in it.

If you can think of a better trick to tell them apart, tweet at me and let me know @Writing_Class.


Is it suppose or supposed? As with most English usage questions, that depends on the context of your sentence.

Suppose is used as a verb. Its past tense is spelled supposed.

Supposed is an adjective and is used in the common phrase supposed to.