When should you use have and when should you use did? I really don't understand the difference in meaning between: "have you seen...." and "did you see....." "have you worked....." "did you work....." My main problem is when I have to use it for writing text. Can anyone clarify this fine point for me as I can't find reference to it in any of my books. Thank you. RM
Did you see television? and Have you seen television? are both correct Have you seen my umbrella? and Did you see my umbrella? are both correct Have you seen my brother? and Did you see my brother? are both correct
but when something follows be careful
Did you see television last night? right
Have you seen television last night? wrong
Have you seen my umbrella last night? wrong
Did you see my umbrella last night? right
Have you seen my brother last night? wrong
Did you see my brother last night? right
With "did", you mean the simple past tense; with "have", you mean the present perfect.
Whether you will use the simple past or the present perfect will depend partly on whether you are writing American English or British English. In many cases you can choose either simple past or present perfect, and in those cases Americans usually use the simple past, and British speakers usually use the present perfect.
The present perfect is used when you want to make a connection between the past and the present. For example:
"Have you seen Pirates of the Caribbean?" Obviously, the action of watching that movie, if it happened, happened in the past; but the speaker is asking if the other person has ever seen the movie in his life, and that person's life continues to the present.
"Have you written the letter I told you to write?" Obviously, the action of writing the letter, if it happened, happened in the past; but the speaker is asking the other person if the letter exists now.
The past perfect is used to describe a past event; if there is a connection with the present, it's not important. For example:
"Did you see Pirates of the Caribbean?" The speaker is asking if the other person saw that movie at a time in the past.
"Did you write the letter I told you to write?" The speaker is asking if the other person wrote the letter at a time in the past.
In such sentences, there is almost no difference in meaning. Americans will usually use the past simple, British people will usually use the present perfect.
However, there are some times when you cannot use the present perfect. Hi_there_Carl has given you some examples, and they all have one thing in common: they mention a specific time in the past. In such cases, mentioning a time in the past means that we are asking about the past, and not about any connection with the present; so we must use the past simple.
Another case would be this one:
"Wow, that's a great story! Did you write this?"
Here, the speaker already knows the story exists now, because he's reading it; he's not interested in any connection with the present. He's asking about the identity of the author, so the focus is on the past action itself.