Cambridge Grammar of English Hardback with cd-rom a comprehensive Guide

Modal expressions

144e

Will/shall/’ll

An academic writer/speaker may use will/shall/’ll to refer forward in a written

text or in an academic presentation (e.g. a lecture), to outline or point to things

which are to be found later in the text. 

Both simple and progressive forms are used. Progressive aspect is especially

used when the writer/speaker refers to events which will be repeated or be

constant over longer stretches of text.

Shall

, especially, indicates an undertaking by the writer/speaker to do the

action referred to:

Radiant energy plays a vital role in astrophysical scenarios, and often appears

as an equal partner to matter in determining the nature of physical processes

which govern different structures. So we 

shall next consider different types of

radiant energy which exist in nature and how they interact with matter.