с английским Look at structurs a and b. Find tree examples of structure b in the memory quiz on page 6. When do we not use did in a question ?

a. question word + did + subject + main verb
Who did you visit ? I visit my aunt.
Which did you get, the bus or the train ? I got the bus.
( The question word refers to the object )

b. question word + main verb
Who visited you ? My grandfather visited me.
which cost more? the train cost more.
( The question word refers to the subject )
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