The term “accentual” refers to stress. In other words, the placement of stress is determined by intonation. It is said that word stress is independent of intonation and intonation is carried by the stress syllables of a tone-unit. So, what is the deal with the accentual function of intonation and the placing of stress?
The aspect of the stress as part of the intonation is the placement of the tonic stress within the tonic-unit.
One thing that is of a great linguistic importance is the location of the tonic syllable. Its usual position is on the last lexical word of the tone unit. Below are two examples that show the normal placement and the contrastive placement.
Example 1 – Normal placement
I want to know where he’s \travelling to.
Note: The word “to” is a preposition here, not a lexical word, therefore it is not stressed.
Example 2 – Contrastive placement
I don’t want to know where he’s travelling \/from.
In a similar way, the stressed can be place in other positions for the purpose of emphasis. Below are two examples, the first is non-emphatic and the second is emphatic.
Example 1 – Non-emphatic
It was very \bad.
Example 2 – Emphatic
It was \very bad.
As you can see, placement of tonic stress is important and closely related to intonation.