Signal phrases, or lead-in phrases, are expressions that assist you to introduce both direct and indirect citations in different styles.
You should add variety to your writing by using a wide selection of signal phrases or lead-in phrases to introduce quotations, paraphrases, summaries, or information you borrow from external sources.
One of the most used signal phrases is “According to [author*]*…” placed at the beginning of a sentence. There are many other signal phrases that contain verbs such as argue or claim.
It is advised that you choose a signal phrase verb that matches your intention for the use of the integrated source.
Before you finish, ensure that you read the whole sentence several times so that the signal phrase coheres with what you quote and paraphrase in terms of meaning and grammatical accuracy.
Source
