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.

• I say → he says

Consonant before -y: Change -y to -i. Then add -es.

• I worry → he worries