"1 sometime, 2 sometimes, right?"

One more random funny story about how English is ridiculous.  In one of my 3nensei classes, we were having a word test, where I read out words and they have to write them in English and then write the Japanese equivalent. 

The JTE gave me the sheet with the words and I read it.  So one of the words I was supposed to read out was 'sometimes.'  Let me point out now that in Japanese, 'sometimes' is 'tokidoki' and 'sometime_'  is 'itsuka'  Two different words with different meanings, right?  In English, too, the meaning is different, even if the words are almost the same.  As a matter of fact, even the JTE was confused because on the sheet she gave me, she had written 'sometime (tokidoki.)'  Based on the 'tokidoki' I assumed she meant 'sometimes' so that is what I said.  Anyway, 'sometime' and 'sometimes' caused a great deal of confusion on that word test as students wrote all possible combinations of 'sometime' 'sometimes' 'tokidoki' and 'itsuka.'  And when I wrote the correct answer 'sometimeS' and the JTE said 'tokidoki,' and said that 'sometime' was wrong unless they had 'itsuka' written as the meaning, they were like "EEEEEEEHH?  NANDE? (why) 1 apple, 2 apples,  1 sometime,  2 sometimes, right? Aren't they the same?"