$(G)$ on goods and services:

An increase in aggregate expenditure increases aggregate demand $($AD$),$ which increases real GDP$,$ which induces an increase in consumption expenditure $($C$),$ and which further increases aggregate demand $($AD$).$

An increase in aggregate expenditure increases aggregate supply $($AS$),$ which increases real GDP$,$ which induces an increase in consumption expenditure $($C$),$ and which further increases aggregate supply $($AS$).$

An increase in aggregate expenditure decreases aggregate demand $($AD$),$ which decreases real GDP$,$ which induces an decrease in consumption expenditure $($C$),$ and which further decreases aggregate demand $($AD$).$

An increase in aggregate expenditure decreases aggregate supply $($AS$),$ which decreases real GDP$,$ which induces an decrease in consumption expenditure $($C$),$ and which further decreases aggregate supply $($AS$).$