We know that years like 2021 are read as "er ling er yi nian". But Google Translate reads 2000年 as :liang qian nian. Possibly because "er ling ling ling nian" would be cumbersome. So, what's the difference between a) year of 2000 and b) 2000 years
The year 2021 is indeed read as "er ling er yi nian (二零二一年)", or even just "er ling er yi (二零二一)."
The conversational way that you read the year 2000 when you are referring to the specific year is "er ling ling ling nian (二零零零年)", or even just "er ling ling ling (二零零零)." You can also read it as "liang qian nian (两千年)." An example of this could be the following:
"我的生日是在二零零零年一月十九日。(My birthday is on January 19th, 2000)" However, if you are just texting someone or doing informal writing, you can just write out the numbers instead of the Chinese characters: "我的生日是在2000年1月19日"
However, if 2000 represent a time span (say from the year 900 to the year 2900), then 2000 is read as "liang qian (两千)." Similarly, 2961 days is read as "liang qian jui bai liu shi yi tian（两千九百六十一天）."
In general, when you are reading any number that has more than 2 digits and the second to the last digit is a 1 (numbers in the form of x1x, xx1x, xxx1x, etc where x is any number), then you also need to read it differently. For example: 318 days is read as "san bai yi shi ba tiam （三百一十八天）" instead of "san bai shi ba tian (三百十八天)"
Here are some examples of all the concepts mentioned above:
the year 7819: "qi qian ba bai yi shi jui nian （七千八百一十九年）, or qi ba yi jui nian (七八一九年)"
After 4312 years: si qian san bai yi shi er nian zhi hou (四千三百一十二年之后). Some people read it as "si san yi er nian zhi hou (四三一二年之后)," but it is very very very very very rare.
The answer to your question: The difference between a) the year 2000 and b) 2000 years is huge. See the following:
a) Means a specific year, and you can read it in two different ways:
- liang qian nian (两千年) (this way is less common)
- er ling ling ling nian (二零零零年) (more common, used in both formal and informal conversations)
On the other hand, b) means a time span, so it can only be read as liang qian nian (两千年).
Reading the year 2000 as "er ling ling ling nian" is not cumbersome at all. Probably Google Translate thought you were talking about a span of 2000 years (which is case b)) so it read 2000 as "liang qian nian"
Hope that helps :)