walkd的变形属于规则变化，所以walk的过去式和过去分词在原形后面直接加_ed,即walked。
例句：
1 He walked towards the summerhouse, at first furtively, then with more confidence.
他朝凉亭走去，开始还偷偷摸摸地，后来就壮大了胆子。
2. Michael gave him a dirty look and walked out.
迈克尔狠狠地瞪了他一眼然后走开了。
3. They walked right into a booby-trap and got blown to smithereens.
他们正好踩上了饵雷，结果被炸得粉身碎骨。
