S in Morse Code
The letter S is the nineteenth letter of the English alphabet. S in Morse code is sent as …, three short signals in a row. It is also the first and last letter of the distress signal SOS.
S in Morse code: pattern and timing
- Dots: 3
- Dashes: 0
- Total length: 5 time units (three dots, plus two gaps of 1 unit each)
S is made only of short signals, so the sound is a quick burst of three equal taps. The gaps between the three taps are one unit each, and that even spacing is what makes S easy to recognize as one letter.
How to hear S
S is “dit-dit-dit”: three short, even taps. Listen for three quick sounds with no long pauses between them. A letter that gives a fourth tap is not S, and a letter that gives two taps is I.
Letters that sound similar
S is easy to confuse with letters whose pattern differs from it by one signal:
- H (….): one more dot, so four quick taps instead of three
- I (..): one dot fewer, so two quick taps instead of three
- U (..-): the last tap is long instead of short
- R (.-.): the middle tap is long instead of short
- V (…-): the last tap is long, with three short taps before it
- B (-…) and D (-..): the first tap is long instead of short
The quickest test is to count the taps and check whether any of them is long. S has exactly three taps, all short.
Words that use S
- SEE: … . .
- SAFE: … .- ..-. .
- STOP: … – — .–.
- SAY: … .- -.–
Letters are separated by a single space, and words by a slash (/). Check these words in the Morse code to text decoder, or see the full SOS page for the distress pattern.
Practice
Practice S next to H and I with the Morse code practice tools. Counting the taps is the fastest way to tell them apart. For the full chart, see the Morse code alphabet page.
How long the letter lasts at 20 WPM
At 20 words per minute, one time unit lasts about 60 milliseconds. S is 5 units long, so the whole letter takes about 300 milliseconds, with its three dots and the two gaps between them. Hearing that rhythm at a steady speed is the goal of practice.
The timing rules for every letter follow the International Telecommunication Union recommendation ITU-R M.1677-1.
Words that use S
- SEND: … . -. -..
- SAME: … .- — .
- STAY: … – .- -.–
- SHIP: … …. .. .–.
- SIX: … .. -..-
- SIGNAL: … .. –. -. .- .-..
Learning S in Morse code is easier when you hear it inside words. S is the first letter of many common words, and it is the middle letter of others. Each word above starts with three short taps. When you hear that opening burst, the next sounds tell you which word it is.
Practice drill for S
Send S in Morse code five times in a row at 15 WPM, then send SIX and SHIP. Listen for the three even taps each time. If a fourth tap appears, you are hearing H, not S. If the first tap is long, you are hearing B or D.
Why S is important in emergencies
Because S is made only of short signals, it is easy to send with a flashlight or by tapping. That is one reason SOS, which is three S letters sent as one continuous pattern, is the most widely recognized distress signal. The SOS page explains how to send it by sound, light, or tapping.
Frequently Asked Questions
What is S in Morse code?
S in Morse code is … (three dots), the simplest multi-signal letter.
How long is S in Morse code?
S lasts 5 time units in total, including the gaps inside the letter.
Which letters sound like S?
H (four dots) and I (two dots) are the closest, because each differs from S by one dot. U and R have one long signal instead of a short one.