Building on the skills learned at the A2 level (wherein which is appears as the object in non-defining clauses), learners at the B1 level can use a non-defining relative clause with who as the object.

B1 50x33   What I liked most was the friend I made there, a green-eyed chubby boy, who I played with till dinnertime, when I had to go home. (Cambridge English: Preliminary; Portuguese)

B1 50x33   She turned around and, she couldn’t believe it, it was an old classmate Tom, who she hadn’t seen for ages! (Cambridge English: Preliminary; German)

Learners can also use a defining relative clause with who as the object.

B1 50x33   My friends are the people who I love most. (Cambridge English: Preliminary; Spanish - Latin American)

B1 50x33   They filmed two actors who I don’t really know arguing and kissing after it. (Cambridge English: Preliminary; Catalan)

B1 50x33   It was Sarah, a girl who I met in Spain on my holiday last year. (Cambridge English: Preliminary; Swiss German)

B1 level learners are able to use both defining and non-defining relative clauses with the phrase whose name.

B1 50x33   We have a new employee whose name is Mary Watts. (Cambridge English: Business Preliminary; Spanish - European)

B1 50x33   It was a very famous football player, whose name was known all over the world. (Cambridge English: Preliminary; Russian)

B1 50x33   He has got a friend whose name is Robert. (Cambridge English: Preliminary; German)

Learners use defining relative clauses with the phrase the reason why to give an explanation and to add focus.

B1 50x33   The reason why I love it is that it’s quite original because it’s about a woman who can see ghosts. (Cambridge English: Preliminary; Spanish - European)

B1 50x33   This is the reason why we are changing our working hours. (Cambridge English: Business Preliminary; German)

B1 50x33   This is the main reason why it is so famous and popular as well. (Skills for Life: Entry 3; French)

B1 level learners can also add focus by use defining relative clauses with when to define nouns relating to time.

B1 50x33   The day when he had to go back to Korea, I could not stop myself crying. (Cambridge English: Preliminary; Korean)

B1 50x33   I really remember the day when I lost my suitcase in the airport. (Cambridge English: Preliminary; Spanish - Latin American)

B1 50x33   I was in the class at the time when they made the movie, so you will be able to see me on TV. (Cambridge English: Preliminary; Polish)

Learners use defining relative clauses with where to define nouns referring to place.

B1 50x33   The city where I live is very nice and extremely charming. (CELSP)

B1 50x33   But if they are going to a place where you go every year you should go with your friends, you will have more fun. (Cambridge English: Preliminary; Spanish - European)

B1 50x33   We went to the area where I used to live when I was a child near the Highlands. (Cambridge English: Preliminary; Czech)

Finally, learners at the B1 level are able to use defining relative clauses with the pattern the + noun + who / that as a focusing device. However, this form is most frequently used by learners who speak romance languages.

B1 50x33   The thing that was great is that the weather was really warm and it didn’t rain. (Cambridge English: Preliminary; French)

B1 50x33   The thing that I love most is going to the shops. (Cambridge English: Preliminary; Spanish - Latin American)

B1 50x33   The person who called me was my best friend. (Cambridge English: Preliminary; Catalan)

So, at the B1 level, learners expand on the progress made at A2, using who as an object in defining and non-defining relative clauses. Once the B1 level is achieved, the pattern the + noun + who / that becomes a feature in learner work. Additionally, learners use where, when and a few key phrases (whose name and the reason why) within relative clauses. As learners move on to the B2 level, whose will be used more frequently and in a wider variety of contexts.

Cambridge University Press