print "Hello " . $name . ".\n";       # not bad
print "Hello ", $name, ".\n";         # hope no-one set $,
print "Hello $name.\n";               # nice and clear

print "Hello " . f($x) . ".\n";   # this is usually what I like
print "Hello ", f($x), ".\n";     # has the advantage of print a list of return values from the function without needing join (which is good and bad)
print "Hello @{[ f($x) ]}.\n";    # feel free to sit and stare inexperienced Perlers and maintainers