Help with subgroup modifier please

[ShriramV630]

Hi Manhattan GMAT,

Can I ask you one question with subgroup modifier, please.

In the MGMAT there is this example in page no 240.

Right: This model explains all known subatomic particles, some of which were only recently discovered.

the associated example includes.,

Wrong: This model explains all known subatomic particles, some of which only recently discovered.

I understood that WERE is a must when using the which construction.

In the page no 250 MGMAT has a similar sentence that is correct according to MGMAT but the sentence is lacking WERE.

The houses on the canal street, many of which had been damaged in the storm, looked abandoned.

My question,

Is it compulsory to use the word WERE when referring to subgroup while the using the WHICH construction.

Please could you help me with this.

[RonPurewal]

hi,
questions about MGMAT books should be posted in the MGMAT non-CAT folder.
thanks.