Spelling of Words in the Present Simple
How to add -s to the infinitive in the Present Simple
You must be careful with some words when using the 3rd person singular.
1. verbs ending in a sibilant [s] [z] [ʃ] [ʒ] [ʧ] [ʤ] or verbs ending in -o preceded by a consonant
We add –es to the infinitive.
- I search → he searches
- I kiss → he kisses
- I go → he goes
- I do → he does
2. verbs ending in -y
Mind the letter that stands before -y.
Vowel before -y: Add -s.
Consonant before -y: Change -y to -i. Then add -es.