hardy, hearty, hardly, heartily, hardily

Hardy or hardy, when used to describe people, means able to withstand fatigue, hunger, or exposure to the weather--
Our soldiers are hardy enough to survive for days on the rations in their packs.
These young people may not be hardy enough for a camping trip.

Hardy or hardy, when used to describe plants, means able to survive a cold winter or a drought--
This shrub is guaranteed to be hardy enough to survive  freezing weather.
This plant isn't hardy enough for this region, but it may be used as an annual.

Hearty or hearty ( almost rhymes with hardy ) means unrestrained, enthusiastic, or vigorous--
His hearty greeting made everyone feel at ease.
They ate with a hearty appetite after the long walk.
Hearty may be used to describe a filling, warming, or nourishing meal--
A hearty bowl of soup will warm us up.

Hardly or hardly means barely, or almost not at all--
We could hardly see the fireworks through the fog.
Speak up; we can hardly hear you.

Hardily or hardily is an adverb ( describes an action), meaning in the manner or way of someone who can survive hardship or endure deprivation--
Life at camp taught them to live hardily.

Heartily or heartily is an adverb ( describes an action ), meaning in an enthusiastic or unrestrained manner--
He welcomed them heartily, and offered them a drink.

Now that you know that, you can say--
"Campers who aren't hardy enough can hardly stand the climb", he said heartily. "They'll go at it hardily after a hearty meal."

Note--"hardy" or "hardie" is also the name of a metalworking tool, similar to a chisel--
This is the wrong tool. You'll need a hardy.

Note # 2--"Hardy"  ( a proper noun, and always capitalized ) may also be a family name or surname--
Our literature class is reading a novel by Thomas Hardy.

Note # 3--"hearty" is also an old-fashioned word for a sailor or shipmate, more familiar in its plural form of "hearties"--
There's grog for all of me hearties.