Dino mummy:My DS2 is currently in P3. So far, I have no complaints on his teachers for this year. The teachers are committed & responsible. His grades did dropped this year esp Chinese, mainly cos he is not good at oral and compo. He can't understand the oral topics (conversation) and he can't write the compo. I understand that there are remedial classes conducted for his class.
As for inappropriate words used in class, you can feedback to the Principal. I know of 1 parent who fedback to Principal when he heard 1 teacher shouting to the P1 during orientation.
For relief teachers issues, can also feedback to Principal / VP. I did that last year cos my DS2's co-FT who taught the class Eng and Maths was a relief teacher, untrained. From the incidents mentioned by my DS2, the co-FT couldn't handle the rowdy class. The timetable was not followed at times so some days, there was no lesson on Eng and some days, no lesson on Maths. VP told me there was manpower issue and mentioned the manpower may come in mid of last year. Aft the feedback, I realized there were minor changes like VP will \"spot check\" class, other trained teacher will stand in etc. Till Term 3, the class finally had a trained co-Form.
Talk to the teachers if you have concerns over your kids' studies...it should help.
Dino mummy, your DS2 so lucky to have remedial for Chinese.