Ответь на вопрос: did she buy a book yesterday?

Yes,  she did.  she bought  a book yesterday. или  так:   no,  she did  not.  she did not buy a book yesterday.

Yes she did вот так вот

the computer turned into a universal remedy for processing of all types of information used by the person. since childhood we get used to fascinating computer games, fascinating "teaching tools"; we learn to read, write, draw, without departing from the screen; right there we watch movies, we listen to music. our parents by means of this car make and transfer documents, write business letters, communicate with colleagues on business. modern achievements allow to contact quickly the help of the internet with an every spot on the globe and to learn about all the newest information. by means of the computer it is possible to develop the situation of the house corresponding to all tastes and desires of the person, to pick up suitable style in clothes, a hairdress, cosmetics and many other things.certainly, all this is very important for the person. therefore the advantage of the computer is huge. but recently scientists and physicians began to say even more often that this device isn't too safe for human health. we so got used that a lot of things can be made by means of the car that we wouldn't like to write, make independently even the simplest calculations.

глагол(v) в present simple употребляется в обычной форме, но в 3 лице ед. числе (после he/ she/ it) глагол принимает окончание -s

 

he reads a lot of books every day. 

 

если глагол оканчивается на -s, -ss, -sh, -ch, -tch, -x, -z, -zz то прибавляется окончание –es.

 

mix-mixes

 

если глагол оканчивается -y с предшествующей согласной то y меняется на i + окончание -s

 

  cry - cries

 

  eсли глагол заканчивается на -о то прибавляем окончание -es

 

do - does

 

для того чтобы сделать предложение в present simple отрицательным необходимо поставить глагол do/does + not перед глаголом. does используется в 3 лице ед. числе (после he she it). когда мы используем does глагол используется без окончания -s 

 

do not work / does not work или сокращенная форма: don’t work / doesn’t work

 

  единственное множественное1 i will learn/study/read we will learn/study/read2 you will learn/study/read you will learn/study/read3 he, she, it will learn/study/read they will learn/study/readвопросительные

  единственное множественное1 will i learn/study/read? will we learn/study/read? 2 will you learn/study/read? will you learn/study/read? 3 will he/she/it learn/study/read? will they learn/study/read?

 

отрицательныелицо числоединственное множественное1 i will not learn/study/read we will not learn/study/read2 you will not learn/study/read you will not learn/study/read3 he, she, it will not learn/study/read they will not learn/study/read