Three pupils tell Children's Express* what they think about supply teachers voices.
Jason Leech, 10, is in Year 5 at Grange junior school in Letchworth, Hertfordshire.
All supply teachers forget your name - especially mine. I get called Jack or John. Once I even got mixed up with Ashley, but I suppose he's got blond hair like me.
I prefer to just have one teacher because supply teachers get lessons muddled up. You don't get to do good lessons like PE because they never know when it's time to go to the hall. The headteacher or another teacher should tell them what lessons you should have but they are always too busy to tell them properly.
I had a supply teacher for about a month because my teacher was really ill. It was a pain because it was my first-ever supply teacher. I don't like getting tugged around by different teachers.
Tom Vaughan, 10, is a pupil at The Harrodian School in Barnes, south London.
Supply teachers give you a new angle on your work. They don't say: "Sure, do whatever you like"; they always say: "No, you have to learn, learn and learn." Also, supply teachers never say: "Thank you, that's very good work." Instead they say things like: "Well I don't know. Is that okay with your normal teacher?" Supply teachers don't know enough about you. They don't know if you are naughty or good, which makes me nervous of them. Once a supply teacher pulled me up for something I hadn't done. I was annoyed because my normal teacher would have known I wasn't the type of person to flick a pencil at my friend.
When you have a supply teacher you don't get to do what you were doing in lessons the day before, even if it was something good.
Ahshah-nah Ebanks-Greenan, 6, is in Year 1 at Links first school in Merton, Surrey
The thing about supply teachers is they're always late for assembly. They're told when it is but they always forget and make us walk in late, which is embarrassing.
I've had to have a supply teacher loads of times. Once I had one for a whole week because my teacher broke her leg and she had to stay at home. It's a hard job because they have to shout a lot. People are always naughty and fight because it's not the normal teacher. They do it again when they think the teacher isn't looking but the teacher always knows and has to shout - again!
My advice to supply teachers would be to go home and relax because they always look tired. If they rested they'd be better teachers.
Children's Express is a programme of learning through journalism for young people aged eight to 18. Interviews by editor Lizzie Kenyon, 14, and reporters Milo Cullinan, 11, and Camille Noriege, 13. If any of your children would like to be interviewed by the charity, call Jo Bird on 0171-833 2577.