$\text{1. My friend hasn't eaten fast food since last year.}$

$\text{Công thức : S+ gave up+Ving+....= S+ has/have+not+VPII+...}$

$\text{2. How long have you done charitable work?}$

$\text{Công thức: When+did+S+V+..?= How long+have/has+S+VPII+..?}$

$\text{3. My father stopped smoking in 2004.}$

$\text{Công thức: S+ has/have+not+VPII+...}$= $\text{S+ stopped+Ving+....}$

$\text{*Thật ra câu 1 và 3 chung 1 công thức nha bạn! }$

$\text{Công thức: S+ has/have+not+VPII+...}$

$\text{= S+ stopped/gave up+Ving+....}$

$\text{CHÚC BẠN HỌC TỐT!!! }$

1.My friend gave up eating fast food last year

->My friend has given up eating fast food since last year.

2.When did you star doing charitable?

-> How long have you done charitable work?

3.My father hasn't smoking since 2004.

->My father stopped smoking in 2014.