Chinese tells the time with a number and 点 (diǎn) for the hour, 分 (fēn) for the minutes and 半 (bàn) for half past. The time always comes before the verb, so "I get up at seven" is 我七点起床.
To ask the time, use 几点 (jǐ diǎn, "what time"). To answer, put the number in front of 点. You don't need 是 ("to be"): 现在两点 simply means "It's two o'clock now."
The most common mistake is 二点. For two o'clock, always say 两点 (liǎng diǎn). For twelve o'clock, it is still 十二点, because 二 is only replaced when it stands alone before 点.
Minutes come after the hour: hour + 点 + minutes + 分. For half past, add 半 after 点: 八点半 is half past eight. 半 never goes before the hour.
For minutes under ten, people often add 零 (líng, "zero"): 十点零五分. In everyday speech, 分 is often dropped when the minutes are ten or more, so 七点二十 means 7:20. You may also hear 一刻 (yí kè, "a quarter"), but it is not an HSK 1 word.
The time goes before the verb, usually straight after the subject: 我早上七点起床. Saying 我起床早上七点, following English word order, is a very common learner mistake.
Chinese does not use "am" and "pm". Instead, put a word such as 早上, 上午, 中午, 下午 or 晚上 before the time. When there is a day as well, go from big to small: day, then part of the day, then the hour, as in 明天上午十一点.
点 and 分 give a point in time: 两点 is two o'clock. For how long something lasts, use 个小时 (ge xiǎoshí, hours) and 分钟 (fēnzhōng, minutes): 两个小时 is two hours, 二十分钟 is twenty minutes.
A length of time goes after the verb, not before it: 我学习了两个小时 means "I studied for two hours".
Practise this grammar point on paper: 20 exercises using only HSK 1 words, with an answer key on a separate page. Free to print and copy for your class.
Every example on this page uses only words up to HSK 1. Paste your own sentences into the level checker to see which words, if any, are above your level.