Sustain or Substain? What is the difference?

When distinguishing differences between the words “sustain” or “substain,” “sustain” will always be correct. This means “substain” is an incorrect spelling. As a matter of fact, it’s not really even a word in English. So, remembering this is very easy.

If you get confused, don’t fret. Even native English speakers will say it wrong on occasion. That said, it is rare for native speakers to misspell it when writing. It’s not difficult or confusing, just remember there is no “b.”

What Does “Sustain” Mean?

“Sustain” is either a verb or a noun with several nuances of meaning. As a verb, it references support or strength in a physical or mental way. But, “to sustain” can also mean prolonged suffering or doing something for an extensive period of time without interruption. It can also be a legal term that affirms, upholds, or confirms a judgment.

As a noun, “sustain” references a musical effect held for a long period of time. Therefore, in its basic sense, whether verb or noun, “sustain” refers to something held or incurred.

Correct; Incorrect Use of “Sustain”

Even though “substain” isn’t a word, let’s pretend for a moment that it is. The prefix “sub” indicates something underneath or below. “Stain,” denotes a mark, splotch or patch. Therefore, it would mean an undermark or a stain below. When comparing it with “sustain,” it doesn’t match up. The best way to understand this is to see it in a sentence.


  • Correct: Coffee sustains my well-being in the morning.
  • Incorrect: Coffee substains my wellbeing in the morning.
  • Correct: He sustained severe brain damage after the accident.
  • Incorrect: He substained severe brain damage after the accident.
  • Correct: They can sustain 200 pounds of pressure per minute.
  • Incorrect: They can substain 200 pounds of pressure per minute.
  • Correct: The judge sustained the objection raised by the defense.
  • Incorrect: The judge substained the objection raised by the defense.


  • Correct: Jimi Hendrix is famous for his sustain of a single guitar string.
  • Incorrect: Jimi Hendrix is famous for his substain of a single guitar string.


As you can see, “substain” doesn’t make sense in the same context as “sustain.” Sustain, whether verb or noun, indicates holding something for a considerable period of time. Although there are nuances, “substain” would indicate something under or below. It simply doesn’t fit the same definition as “sustain.”