But keep in mind also that 'were' is also past tense (but not for I). The past simple tense goes like this for the different persons: I was, you were, he/she was, we were, you (plural) were, they were So: This morning I was hungry. This morning you were hungry. This morning he/she was hungry, This moring we were hungry. This morning you (plural) were hungry. This morning they were hungry.

You can use "were" after if . For instance, "If I were you then I will read" . I asked a question close to yours so you may want to check it http://www.italki.com/question/256339

If you are just saying a past tense sentence, say I was. Eg I was hugry this morning. If you are saying something hypothetical, say I were. Eg. If I were hungry I would eat, but I am not hungry, so I will not eat.

ex: If i were you i will learn Arabic too

I was