This page is brought to you by the OWL at Purdue University. When printing this page, you must include the entire legal notice.
Copyright ©1995-2018 by The Writing Lab & The OWL at Purdue and Purdue University. All rights reserved. This material may not be published, reproduced, broadcast, rewritten, or redistributed without permission. Use of this site constitutes acceptance of our terms and conditions of fair use.
In most citation styles, including APA, MLA, and Chicago style, you can add variety to your research writing by not always using the same sentence structure to introduce quotations, paraphrases, or pieces of information borrowed from different sources. It is relatively simple to use a wide variety of different expressions to introduce both direct and indirect citations. These expressions, which usually occur in the parts of sentences that come just before quotes and paraphrases, are called signal phrases (or, in some cases, lead-in phrases).
Often, signal phrases can be distinguished by the presence of a verb like "indicate" or "argue" that references what the author is doing in the original source. However, a few select signal phrases contain no verbs (e.g., "According to [author],").
In the examples below, the author being cited is Jane Doe. The examples in the first section are adapted to APA, which recommends past-tense verbs in signal phrases. For MLA (as well as Chicago style), the same verbs can also be used in the present tense instead of the past tense, as the second section below shows.