when we will use is and was .

We use "is" as a helping verb with he, she,it,any single name, singular noun in simple present tense(when there is no verb in the given sentence) as well as in present continuous tense. For ex:- He is a good student. Is Ranu going to that school? "Was" is used as a helping verb with I, he,she,it,any single name, singular noun in simple past tense(when there is no verb in the given sentence) as well as in past continuous tense. Ex:- Was I a queen? She was not writing.