Greek sigma has two lowercase shapes. Your task is to choose the shape from its position in the written word, not to learn two separate alphabet letters. Start by comparing each lowercase word with its capital form. Then cover the examples and complete the missing letters below.
New to the Greek letters? Start with the complete Greek alphabet guide: all 24 letters, their names and how they sound.
Compare lowercase and capitals
| κόσμος | ΚΟΣΜΟΣ |
| σπίτι | ΣΠΙΤΙ |
| θάλασσα | ΘΑΛΑΣΣΑ |
| φίλος | ΦΙΛΟΣ |
Look inside the word and at its end
Κόσμος means world and contains both shapes: σ inside the word and ς at the end. Σπίτι means house and begins with σ. Θάλασσα means sea and has two σ letters inside it. Φίλος means friend and ends with ς. Use ordinary σ at the beginning or inside a lowercase word, and final ς at its end.
Keep punctuation outside the spelling decision
A comma, full stop or exclamation mark does not turn the final letter into an internal one. The final sigma remains ς in φίλος, and φίλος! because the word has ended. A space then begins a new word. In Ο φίλος μου, “my friend”, μου is a separate word: its following letters do not change the final ς of φίλος.
Return to one capital shape
Both lowercase forms become Σ in capitals. That is why ΚΟΣΜΟΣ contains Σ twice, although κόσμος uses two shapes. When returning to lowercase, inspect the position of each sigma separately. In these all-capital examples the stress mark is absent; restore the normal lowercase spelling shown in the table rather than guessing its stress.
Fill the gaps with σ or ς
- Write the complete word: κό_μο_.
- Write the complete word: θάλα__α.
- Complete the word before the exclamation mark: φίλο_!
- Complete the word beginning: _πίτι.
Show the answers
1. κόσμος: σ inside, ς at the end. 2. θάλασσα: both letters are inside the word, so both are σ. 3. φίλος!: the punctuation follows a completed word. 4. σπίτι: σ begins the word.
Check your own copying
Write ΚΟΣΜΟΣ and ΣΠΙΤΙ in lowercase without looking at the first column. Circle the final letter of each word. Only one of these two words ends in sigma, so only one needs ς. Compare your answers with the table and check the stress marks separately.
Continue with the Greek alphabet lesson or practise reading Greek capital letters on signs.