# Restrictive and non-restrictive relative clauses

I have a question about restrictive and non-restrictive relative clauses.

These are the original sentences:

The first plants to grow are pioneer plants. Pioneer plants can survive in harsh conditions.

Now if I am supposed to combine these sentences, which one is correct?

a) The first plants to grow are pioneer plants which can survive in harsh conditions.

b) The first plants to grow are pioneer plants, which can survive in harsh conditions.

I already know the difference between sentences, however, in a book called "Writing for IELTS", the second one is considered correct. But I, myself, think the opposite.

• Is there more than one kind of "pioneer plant"? Commented Mar 8, 2022 at 19:54

These are the original sentences:

The first plants to grow are pioneer plants. Pioneer plants can survive in harsh conditions.

Now if I am supposed to combine these sentences, which one is correct?

a) The first plants to grow are pioneer plants which can survive in harsh conditions.

b) The first plants to grow are pioneer plants, which can survive in harsh conditions.

Sentence (a) can be paraphrased as: The first plants to grow are those pioneer plants that can survive in harsh conditions, and not other types of pioneer plants.

Sentence (b) can be paraphrased as: The first plants to grow are pioneer plants, and pioneer plants are the very types of plants that can survive in harsh conditions.

Given your description, sentence (b) is correct because it contains a non-restrictive clause.

The second sentence is correct. The definition of "pioneer plant" seems to be "the first plant to grow". The second clause does not define which pioneer plants can survive in harsh conditions. Rather, it is more information about pioneer plants, so it should be non-restrictive.

It's two separate statements about pioneer plants. It could be rephrased:

Pioneer plants are the first plants to grow. Pioneer plants can survive in harsh conditions.

These two sentences together make sense because plants that can survive in harsh conditions make the ground more fertile for the next plants to start growing there.

• We seem to have interpreted the sentence in different ways. I take it that they are pioneer plants because of their ability to survive, which this seems to confirm. Commented Mar 8, 2022 at 20:02
• @KateBunting Ironically, I think you're both interpreting the source sentence the same; I think you're just misinterpreting gotube's answer. You both seem to be making the same point. Commented Mar 8, 2022 at 22:14
• @KateBunting I understand that the definition of "pioneer plant" is the first plant to grow somewhere. This is the case because they are able to survive in harsh conditions. There aren't any pioneer plants that cannot survive in harsh conditions, so only non-defining makes sense. That's to say, I'm inferring there is no contrast with "pioneer plants which cannot survive in harsh conditions".
– gotube
Commented Mar 9, 2022 at 9:52