From a previous answer by me, which you can go and look up. I have basically answered this question three times.
The past continuous:
The past continuous (also called past progressive) is a verb tense which is used to show that an ongoing past action was happening at a specific moment of interruption, or that two ongoing actions were happening at the same time. Read on for detailed descriptions, examples, and past continuous exercises.
Statement: You were studying when she called. Question: Were you studying when she called? Negative: You were not studying when she called.
The Trick with the Past Continuous
The trick is this: Even if there is not actual "when" or "while" or "as" in the sentence, these are always implied.
There is always the idea of something that defines the moment in time when the was/verbING is being used.
So, "He was saying that he is going to leave soon." would imply either:
as he was getting ready to leave. OR
when we arrived at the house.
Those are examples of implied time limiters.
The he said/he says examples are obvious. One is present; one is past.
The present continuous can be used with a simple past tense.
He said we have a good chance of winning the game.
He said it in the past, but the game has not yet been played. If the game had been played, he would have said:
He said we had a good chance of winning the game. [the game has been played]
English page past continuous**
Conclusion: If someone asks you:
A person: What were you doing yesterday?
You may answer:
B Person: I was playing tennis.
A Person: Ah, that's why you didn't answer your phone.
[Implication: You didn't answer your phone because you were playing tennis when I called.]
QUESTION: Can you see that the person asking the question had something in mind by using the past continuous? And that it becomes clear at the end of the exchange?
As for what your friend said, there is absolutely no difference here in terms of British or American English. Nothing at all. When telling someone about your day, there would be no reason to use the past continuous unless it is time limited by implication in the wider conversation. Otherwise, the simple past is best. Sometimes, the wider context of a conversation can color all the tenses used:
CONTRASTING CONVERSATIONAL SCENARIOS
- John wants to tell his friend what he was so busy doing laundry yesterday that he didn't answer any of his phone calls.
- John wants to tell his friend what he did yesterday so his friend can understand how busy he really was.