what is the difference between "i wrote" and "i was writing"
The expression 'I wrote' is in simple past while 'I was writing' is in past continuous tense.
Past Indefinite is also known as Simple Past. Simple past tense is used for an action completed in the past. It might occur with or without adverbs of time. It is also used for past habits. Instances for the same are:
The steamer sailed yesterday.
They left school last year.
The past continuous tense (also called the past progressive tense) is commonly used in English for actions which were going on (had not finished) at a particular time in the past. This tense was formed using two components: the verb BE (in the past tense), and the -ING form of a verb.
The following instances would make it clear:
1. It was raining when they left;
2. I was cooking when the phone rang;
3. They were practicing when it started to rain, etc.