Bangkok Poll surveyed 1,218 people aged from 15-35 who live in the capital or close by.
Of those polled, 77 per cent said they had seen strangely spelt and bizarre words on LINE chats and Facebook comments.
Other sources of grammatically wrong words were friends, media personalities and TV or movie characters.
Asked why they used bizarre words, about 39 per cent said they simply wanted to catch up with trends while 32 per cent said the words were short, easy to spell and efficient.
Almost 27 per cent said they felt the words were humorous and eased stress.
So far, 85 per cent believe the language has reached a critical stage and a serious campaign should be initiated to reverse this bad trend.
The survey found that people who influence the use of Thai language the most are actors, actresses, singers, media personalities, reporters, teachers and lecturers.
Assoc Prof Pitinan Suttasarn, who was named an outstanding Thai-language user this year, expected teachers to help children master the use of Thai.
“It’s necessary that teachers encourage their students to practice on a regular basis,” she said.
Pitinan said all teachers – not just Thai-language teachers – and parents must guide children on how to use the language properly.