why is "that are" omitted in the first line?

[Truth4vahid]

why is "that are" omitted in the first line? "Antigens systems (that are ) important in transfusion ..."

 

[Truth4vahid]

EF source says: [FONT=&quot]'That' is often used to introduce defining relative clauses when they follow the words [/FONT]something, anything, everything, nothing, all[FONT=&quot] or a superlative. It may be omitted when it is not the subject of the clause.

So what here?[/FONT]

 

[probus]

I don't see how adding "that are" changes the meaning or improves understandability. In general, good style favours the briefer of two equivalent options. In my opinion, therefore, the passage is better with "that are" left out.

 

[PaulMatthews]

Antigens systems important in transfusion

Nothing has been omitted. The underlined adjective phrase is a post-head modifier of "antigens systems".

We could also have Antigens systems that are important in transfusion, where the underlined element also modifies "antigens systems", but this time it is a relative clause, not an adjective phrase.

There is no difference in meaning between the two constructions.

 

[probus]

What does EF source mean, vahid?

 

[Truth4vahid]

What does EF source mean, vahid?

I mean ef.com
An English learning website that has written some stuff about the relative clause "that".