buy -> покупать
Образование времен (Действует субъект! - Актив т.е. действительный залог):
  Past - ПрошлоеPresent - НастоящееFuture - Будущее
Simple - Факт
I/he/she/it/we/you/they
bought
did buy
----
did not buy
did'nt buy
I/we/you/theyhe/she/it
buybuys
do buydoes buy
----
do not buydoes not buy
do'nt buydoes'nt buy
I/he/she/it/we/you/they
will buy
 
----
will not buy
won't buy
Continous - процесс
I/he/she/itwe/you/they
was buyingwere buying
----
was not buyingwere not buying
Ihe/she/itwe/you/they
am buyingis buyingare buying
----
am not buyingis not buyingare not buying
 is'nt buyingare'nt buying
I/he/she/it/we/you/they
will be buy
----
will not be buy
won't buy
Perfect - Завершенность
I/he/she/it/we/you/they
had bought
----
had not bought
had'nt bought
I/we/you/theyhe/she/it
have boughthas bought
----
have not boughthas not bought
haven't boughthasn't bought
I/he/she/it/we/you/they
will be bought
----
will not be bought
won't be bought
Perfect Continous - Процесс в периоде
I/he/she/it/we/you/they
had been buying
I/we/you/theyhe/she/it
have been buyinghas been buying
I/he/she/it/we/you/they
will have been buying
buy -> покупать