PRESENT SIMPLE TENSE

In this simple present tense, most regular verbs are conjugated with the infinitive or root form, excluded in the third-person singular which ends in –s.

However, for some verbs, the third-person singular often ends with the –es instead of –s. In typical, these verbs have the final letters like o, ch, sh, th, ss, gh, or z.

S + tobe => I am… You/We/They are… He/She/It is…

S + V => I/You/We/They: V (infinitive) He/She/It: V 

To be:            S + am/is/are + NOT + O

Regular verb: S + do/does + NOT + V _ inf

To be:              Am/is/are + S + O?

Regular verb:   Do/Does + S + V _ inf?

For example:

Are you from China? No, I’m not. (You cannot say: No, I'm not)