"Faggot" and "gay boy" are terms most people consider taboo. But, for many teachers, they are just part of everyday life.
A TES survey reveals that 75 per cent of lesbian and gay teachers have experienced discrimination at work. One in five said that they were scared to go to work as a result of school-based harassment.
The survey of 104 teachers was carried out by The TES and the Teacher Support Network charity, in advance of Lesbian, Gay, Bisexual and Transgender history month, in February.
Respondents said that they are regularly confronted with homophobic language. One gay teacher said: "The worst insult that students can say to each other is 'faggot' or 'gay boy'. This doesn't bode well for the acceptance of gay teachers."
Almost three-quarters of respondents said that they had been discriminated against by pupils, while 47 per cent said that casual homophobia was also to be found in the staffroom. A lesbian teacher from London said that she was frozen out by colleagues, after she danced with her girlfriend at a staff party.
Others found that colleagues were unable to separate their sexuality from their ability to do their job. One respondent said: "One colleague (told) the IT supervisor that he should look through my records to make sure I wasn't accessing gay websites at school, simply because I was gay."
And a gay teacher from Yorkshire says that senior management regularly discriminated against him. "When transporting children to after-school activities, I was made to have an additional adult in the car with me," he said. "Heterosexual members of staff were not."
Teachers responding to the survey claim that harassment has led to problems including loss of confidence, stress, and reduced classroom effectiveness.
Patrick Nash, chief executive of the Teacher Support Network, said: "The negative experiences of homosexual, bisexual and transgender teachers are widespread, leaving them feeling stressed, alienated and unsupported.
"It is important that schools have codes of conduct in place, which relate specifically to homophobic issues."
While 60 per cent of schools have a code of conduct to deal with sexual harassment, only a third had one to deal with homophobic discrimination.
Nonetheless, more than half the respondents felt supported by their colleagues, and said they would be happy to come out as homosexual at school. One male teacher from the West Midlands believes that being open about his sexuality has helped his colleagues to overcome their homophobia.
"One school I worked at had two homophobic teachers," he said.
"But when I left for promotion they said that working with me had changed their opinion."
The annual LGBT history month, which aims to draw attention to the achievements of lesbians and gays, was launched last year with support from the Department for Education and Skills. This year, it contributed pound;20,000 towards the project.
The month has been highly controversial and has been criticised in the press. The Daily Mail's ran a story claiming that "children as young as seven could be taught gay history". It also claimed that campaign lesson plans would introduce pupils in primary schools to sexual language and swear words.
This was in response to the teaching resources on the LGBT history month website which suggest that teachers should discuss with children the unpleasant names they call one another in the playground.
The website says: "This will provoke some embarrassment ... as many of the words will be sexual or swear words."
Sue Sanders, co-chair of teachers' organisation Schools Out, which is helping to organise the month, said: "Children use the word 'gay' to describe anything they don't like. People immediately assume that LGBT month is talking about sexuality. We are not. We are talking about identity. We want people to be proud of who they are."
A series of teaching resources is available on the LGBT history month website. Suggested classroom activities include debates on the difference between teasing and bullying.