Connecting sentences
Use:
Type of connection
When comparing contrasting and for unexpected situations
alternatively, by contrast, and whereas.
Reason and result
consequently, therefore, hence, thus, in so far as
Adding information
furthermore, what's more
Time
whenever, meanwhile, subsequently

Examples:
Working in these difficult conditions can be exhausting whereas it could be worse.
The team was productive, hence the bonus.
Alternatively, another solution could be offered.