yīkuàir
他俩过去在一块儿上学，现在又在一块儿工作。
tā liǎ guò qù zài yī kuài r shàng xué, xiàn zài yòu zài yī kuài r gōng zuò.
The two of them used to study together in the past, and now they work together again.
他们一块儿参军。
tāmen yīkuàir cānjūn.
They joined the army together.