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Using when in adjective clauses. The type of adjective cost you will
be learning is how to use when plus the subject and verb. Now what type of nouns do
you think when modifies? Well, time words. Some examples of nouns
of time include time, season, morning, period, moment, anniversary,
year, month and day. But of course there are many
other words that refer to time. Now, take a look at
these different images, which time period do
these images represent? The 1940s, the 1950s, or the 1960s? The correct answer is the 1950s. So let's talk about the history. Now one thing that I can
say about the 1950s, is that the 1950s was a time when
many great products were introduced, such as a color TV, Lego toy,
car seatbelt and remote control. Now I think we can all agree
that these are pretty great. Now I bet 1955, was a very exciting
time for both children and adults because 1955 is the year
when Disneyland opened. Also the 1950s was a period in history
when some very important things happened. For example, DNA was discovered,
also NASA was founded. And the polio vaccine was discovered
saving hundreds and thousands of children. Now let's learn a little more
about each of these events. Pay close attention to the use of when
to form adjective clauses about time. The year when Cambridge
scientists Watson and Crick discovered the chemical
structure of DNA is 1953. Since then we have learned so much about all living things
thanks to these scientists. October 1, 1958, is the date when NASA became operational to
begin space explorations. Since then our understanding of our place
in the universe has never been the same. The date when Dr.
Jonas Salk announced the effectiveness of the polio vaccine on
the radio is March 26, 1953. Thanks to Dr. Salk there are almost no
known cases of polio now in the US. Take a look at these sentences. Where is the adjective clause? I've highlighted for you where
the adjective clause begins and ends. Let's take a look. The year when Cambridge
scientists Watson and Crick discovered the chemical
structure of DNA is 1953. October 1,
1958 is the day when NASA became operational to begin space explorations. The date when Dr.
Jonas Salk announced the effectiveness of the polio vaccine on
the radio is March 26, 1953. Now do you remember what I
said about these images? The 1950s was a time when many
great products were introduced. Now let's talk about the adjective
clause in this sentence. We have when, the pronoun,
plus many great products, the subject, and were introduced, the verb and
this adjective clause modifies time. Now the sentence is basically saying, the 1950s was a time many great
products were introduced in that time. There are several different ways
that you can express the same idea. The 1950s was a time in which many
great products were introduced. Notice that with which, you should use a
preposition, the appropriate preposition. The 1950s was a time that many
great products were introduced. And the 1950s was a time many
great products were introduced, using no pronoun. Using when and
no pronoun are the most common forms. Let's take a look at another example. Let's combine these two ideas. 1955 is the year. Disneyland opened in that year. Do you remember how to
complete this sentence? 1955 is the year when Disneyland opened. Here's some other ways that
you can say the same thing. 1955 is the year in
which Disneyland opened. Hmm, we can also say, 1955 is
the year that Disneyland opened, or you can simply say,
1955 is the year Disneyland opened. Let me test your memory one more time. Combine these two ideas,
the 1950s was a period in history. Some very important things
happened in that time. Well the answer is,
the 1950s was a period in history when some very
important things happened. Well done. Well I hope you had fun
going back in time with me. And I hope that you are more comfortable
using, when in adjective clauses. Thanks for watching!