singular subject, plural verb

Why do we say:

"I am eating a sandwich."
"I like reading."
"I jog every morning."

when the personal pronoun "I" is supposed to be singular?
And why do we say:

"I was at the party last night."
"I was able to finish the exam before the bell rang."

when the personal pronoun "I" took the singular form of the present tense of the verb?

[Francois]

"I" is always singular.

FRC

[Casiopea]

Originally Posted by jean

Why do we say:

"I am eating a sandwich."
"I like reading."
"I jog every morning."

when the personal pronoun "I" is supposed to be singular?

In English, the subject and the verb agree in number, like this,

Verb BE: I am/You are/She is/He is/It is/They are/ We are
Verb Like: I like/You like/She likes/He likes/It likes/They like/We like
Verb Jog: I jog/You jog/She jogs/He jogs/It jogs/They jog/We jog.

The paradigms above show set pairs: I like, I am, I jog

Singular: I am, I like, I jog
Plural: We are, We like, We jog

The only way to tell if the verb (like, jog) is singular or plural is to look at the Subject: "I" means, one person (i.e., it's singular) and "We" means, more than one person (i.e., it's plural). :D

Originally Posted by jean

And why do we say:

"I was at the party last night."
"I was able to finish the exam before the bell rang."

when the personal pronoun "I" took the singular form of the present tense of the verb?

'was' is the past tense of the verb BE:

I am -> I was
You are -> You were
She is -> She was
He is -> He was
It is -> It was
They are -> They were
We are -> We were

"I am" and "I was" are set pairs. :D