2 sentences for 笔 (bǐ — stroke)

1. 他在这幅画的角落里又添了一笔。

   tā zài zhè fú huà de jiǎo​luò lǐ yòu tiān le yī bǐ.

   He added another stroke to the corner of the painting.

   Source: Dong Chinese Dictionary

2. 写毛笔字的时候，要特别注意如何运笔。

   xiě máo​bǐ zì de shí​hou, yào tè​bié zhù​yì rú​hé yùn bǐ.

   When doing calligraphy, you must pay special attention to how you use the brush strokes.

   Source: Dong Chinese Dictionary