Plural forms of nouns
Most singular nouns form the plural by adding -s. Examples: a cat - many cats; a box - many boxes, a baby - many babies, potato – potatoes.
There are some irregular noun plurals. Examples: a means - many means, species – species, mouse – mice, focus – foci, cactus – cacti, fungus – fungi, nucleus – nuclei, analysis – analyses, diagnosis – diagnoses, thesis – theses, crisis – crises, phenomenon – phenomena, criterion – criteria, datum – data, bacterium –bacteria.
But: virus – viruses!
Ex.12. Fill in the words into the crossword. Write plural of the nouns.
Across: 2. Nucleus 5. Species. 7. Ant 10. Datum 12. Ox 13. Reasons 14. Criterion 16. Analysis 17. Virus 18.Crisis
Down: 1. Thesis 3. Cactus 4. Bacterium 6. Phenomenon 8. Means 9. Fungus 10. Diagnosis 11. Potato 15. Rabbit
Ex.13. Answer the questions.
1. What careers in biology can you think of? 2. Do you like any of them? Which ones and why? 3. Are there any areas of biology that you do not find interesting? 4. What areas of biology do you consider the most important for human society nowadays? Why?