none of you did/has done it alone

[diamondcutter]

Thank you for coming today to attend the graduation ceremony at No. 3 Junior High School. First of all, I’d like to congratulate all the students who are here today. I remember meeting all of you when you were just starting Grade 7 at this school. You were all so full of energy and thirsty for knowledge. And yes, some of you were a little difficult to deal with! But today I see a room full of talented young adults who are full of hope for the future. You’ve all grown up so much and I’m so proud of you.
Although you’ve all worked very hard over the last three years, none of you did it alone.
Source: Go for it! 9, an English textbook for junior high school students in China, Cengage Learning and PEP

For the last sentence above, I think it’s also appropriate to use the present perfect tense in the main clause to agree with the tense in the although-clause like this:
Although you’ve all worked very hard over the last three years, none of you has done it alone.
What do you say?

 

[jutfrank]

Yes, that's reasonable.

 

[diamondcutter]

I’d like to know whether the two tenses are equally good or the present perfect is better.

 

[Tarheel]

What comes after the last sentence?

 

[diamondcutter]

Here's what comes after that sentence:

I hope you’ll remember the important people in your lives who helped and supported you -- your parents, your teachers and your friends. Please consider what they’ve done for you and what they mean to you. Never fail to be thankful to the people around you.

Maybe it’s also good to change “helped” to “have helped” and “supported” to “have supported”?

 

[Tarheel]

Here's what comes after that sentence:

I hope you’ll remember the important people in your lives who helped and supported you -- your parents, your teachers and your friends. Please consider what they’ve done for you and what they mean to you. Never fail to be thankful to the people around you.

Maybe it’s also good to change “helped” to “have helped” and “supported” to “have supported”?

Your suggestion makes more sense to me now. As for your new suggestion, you only need one "helped" (have helped and supported).

 

[diamondcutter]

I’d like to know if I could tell my students that the original past tense for the three verbs (did, helped and supported) is all right, but it’s better to change their tense to the present perfect to agree with “you’ve all worked” and “what they’ve done”.

 

[Tarheel]

@diamondcutter Well, I already gave you my opinion. Are you hoping to hear from somebody else?

 

[5jj]

In a situation like this, where both forms are possible, I hesitate to say that one form is 'better'.

 

[diamondcutter]

Sorry, Tarheel. I didn't quite understand what you meant in #6, but now I got it.