2 sentences

1. 那位老头正在公园里打太极拳。

   nà wèi lǎo​tóu zhèng​zài gōng​yuán lǐ dǎ tài​jí​quán.

   That old man is practicing Tai Chi in the park.

   Source: Dong Chinese Dictionary

2. 老人在公园里打太极拳，动作看起来十分矫健。

   lǎo​rén zài gōng​yuán lǐ dǎ tài​jí​quán, dòng​zuò kàn qi​lai shí​fēn jiǎo jiàn.

   The old man was practicing Tai Chi in the park, and his movements looked very vigorous and nimble.

   Source: Dong Chinese Dictionary