Signal verbs
When you use a source in your writing, demonstrate your evaluation of the source's reliability  by carefully choosing a signal verb to show your understanding of the author's purpose, intentions and the degree to which he affirms his statement. By using signal verbs, you let readers know the context in which the source's statement should be viewed. For example, if you choose the signal verb say instead of prove, you are reporting that the author makes his statement without any substantial support.

Choose your signal verbs carefully so that they genuinely reflect the tone and substance of each cited source.

Here is a list of some signal verbs you can use to show your readers how you have evaluated your sources.
 
 
Signal verbs for evaluating sources
acknowledges 
advises 
agrees 
allows 
analyzes 
answers 
asserts 
assumes 
believes 
charges 
claims 
considers 
criticizes 
declares 
describes 
disagrees
discusses 
explains 
emphasizes 
expresses 
holds 
implies 
interprets 
leaves us with 
lists 
objects 
observes 
offers 
opposes 
points to 
presents 
proposes
recognizes 
regards 
remarks 
replies 
reports 
responds 
reveals 
says 
states 
suggests 
supports 
tells us 
thinks 
wants to 
wishes 
wonders