In writing a survey, would I use the words or phrases written by other people and add the proper citation for that. Sometimes the abstract could gib=ve an enough idea about the work which was conducted by the authors and I need just to summarize it.
To avoid plagiarism, you are not allowed to use the same words or phrases written by others and you have to add the relevant citation for that after appropriately paraphrasing and rewriting these sentences in you own language.
If a significant part of something (e.g. an existing scale/questionnaire) is highly relevant to your survey, I would consider adapting that and providing justification for the adaptation. Sometimes paraphrasing simply compromise the meaning.
How I can know how much the similarities between what I wrote and what the other have written. Is there any tool that I can use to check my paper before submission. And to how percentage the similarity is accepted in journal papers?