Toshokan wa shizuka na basho desu kara, ōkina koe de hanasanaide kudasai.

Since the library is a quiet place, please do not speak in a loud voice.

Jugyō ga hajimarimashita kara, shizuka ni shite kudasai.

Class has started, so please be quiet.

Watashi no heya wa shizuka na node, totemo benkyō ni shūchū dekimasu.

Since my room is quiet, I can concentrate on my studies very well.

Yoru no kōen wa hito ga inakute, totemo shizuka desu.

The park at night has no people around and is very quiet.

Kono apāto no mawari wa, hiru demo amari shizuka de wa arimasen.

The area around this apartment is not very quiet, even during the day.

Kinō no umi wa kaze ga nakute, totemo shizuka deshita.

Yesterday's sea had no wind and was very calm.