When use "yo"?
I'm confused on when to use soy versus simply using the conjugated verb. For example. Do I say "Yo tengo hambre" or just "Tengo hambre". It seems somewhat random when speakers include yo and when they do not.

Any suggestions for helping me understand when I should use "yo" and when I should not?

Thanks!

Question

When use "yo"?
I'm confused on when to use soy versus simply using the conjugated verb.  For example.  Do I say "Yo tengo hambre" or just "Tengo hambre".  It seems somewhat random when speakers include yo and when they do not.

Any suggestions for helping me understand when I should use "yo" and when I should not?

Thanks!

Answer

Hi Doug:

You may omit the pronoun in most cases (there won't be any confusion as the conjugation in this case is unique). However, in some situations, when you need to emphasize or make a contrast, you may use it:

Person 1: Tengo hambre. 
Person 2: Yo también.

Person 1: Vamos al parque.
Person 2: No, (yo) tengo hambre; vamos a comer primero.

Answer

It´s right what the other answers say, it depends on the context. Taking your example:

A: Tengo hambre, ¿vamos a comer?
B: YO no tengo mucha hambre, pero si quieres vamos.

Usually, you add YO when you want to emphasize that you are the subject.

Answer

In most of the cases you may omit it as Andres said earlier, but sometimes you HAVE to use it as for example in:
A: ¿Quién va a la fiesta?
B: YO voy (so in this case you can omit the verb but not the subject)
or in:
A: Carla hizo todo el trabajo pendiente.
B: No, YO hice todo el trabajo pendiente./YO lo hice.

Answer

You must avoid to repeat the pronom for example in this case: "Yo me llamo Doug. [Yo] nací en EEUU. [Yo ] tengo 2 hermanos. [Yo] practico mucho deporte. etc"