3 sentences

1. 这堂国语课，老师讲的是古诗。

   zhè táng Guó​yǔ kè, lǎo​shī jiǎng de shì gǔ​shī.

   In this Chinese class, the teacher taught ancient poetry.

   Source: Dong Chinese Dictionary

2. 《国语》是中国第一部国别体史书。

   《 Guó​yǔ》 shì Zhōng​guó dì​yī bù guó​bié tǐ shǐ​shū.

   The 'Guoyu' is China's first history book organized by states.

   Source: Dong Chinese Dictionary

3. 他在家里讲家乡话，出门则讲国语。

   tā zài jiā​lǐ jiǎng jiā​xiāng​huà, chū​mén zé jiǎng Guó​yǔ.

   He speaks his hometown dialect at home and Mandarin when he's out.

   Source: Dong Chinese Dictionary