1Listen and repeat
The rule: many words of Greek origin ending in -is make their plural in -es: crisis → crises, analysis → analyses, basis → bases. No extra syllable, and the stress does not move.
Listen to the change: the singular ends with a short /ɪs/, quick and relaxed, like in “kiss” (/ˈkraɪsɪs/). The plural ends with a long /iːz/: smile, make the vowel longer, and the s becomes a z, like in “cheese” (/ˈkraɪsiːz/). Don't say “crisisses”!
Singular /ɪs/
Plural /iːz/
2Singular or plural?
Listen to each word (▶) without seeing it, then drag it into the right box (or tap the word, then the box). When you're right, you can read it!
3Listen and write
Listen and type the word you hear, then press Enter or click Check.