a question
In a New Headway book I came accross this question -
Why were luxuries, not necessities, the earliest goods to be traded?

What is the construction of - to be traded- Is it infinitive present passive? Shouldn't it be - that were traded.

Question

a question
In a New Headway book I came accross this question -
Why were luxuries, not necessities, the earliest goods to be traded?

What is the construction of  - to  be traded-  Is it infinitive present passive?  Shouldn't it be  - that were traded.

Answer

Yes - passive present infinitive.  This is correct, and your alternative is also correct.

Answer

I think the first one is something that has to be done in the future and the second one is something that was done in the past. Am I correct?

Answer

A question to you: what do you think the difference is between "the earliest goods to be traded" and "the earliest goods that were traded"? :)