I not only play the guitar，I sing as well（＝I also sing ）.
我不但弹吉他，而且还演唱。
2、as well 在口语中也可用于句中，作“也好，也行”或“倒不如”解，用来缓和语气。如：
You may as well go.
你去也好。
The weather was so bad that we might（just）as well have stayed at home.
天气太坏了，早知道如此，倒不如呆在家里为好。
3、as well 可以直接用于just后，用作应答语（可视为It's just as well、的省略），作“幸亏，幸而；无妨；没关系”解。如：
—We were too late to see the film.
我们去得太晚了，没有看上电影。
—Just as well、I hear it isn't very good.
不必遗憾，我听说电影也不怎么样。
