I am not a native speaker.
So, don't trust me. ;)

Friendly can be used as adverb, but not often. It's synonym is "amicably" in this case.
E.g. The natives used us friendly. (ABBYY Lingvo Dictionary)

Now "in a friendly way" is used instead of friendly (adv.)

Good luck!

I see it this way:

It is one (=car) of his girlfriend's.

Article is missing, but it's OK for fluent speech perhaps. :)

From CollinsCobuild:

-year-old combines with numbers to describe the age of people or things. She has a six-year-old daughter. ...their 200-year-old farmhouse in Ohio.
-year-old also combines to form nouns. Snow Puppies is a ski school for 3 to 6-year-olds.

Do you really want it?

The European Commission has just announced an agreement whereby English will be the official language of the EU rather than German which was the other possibility.

As part of the negotiations, Her Majesty's Government conceded that English spelling had some room for improvement and has accepted a five year phase-in plan that would be known as "Euro-English".

In the first year, "s" will replace the soft "c". Sertainly, this will make the sivil servants jump with joy. The hard "c" will be dropped in favour of the "k". This should klear up konfusion and keyboards kan have 1 less letter.

There will be growing publik enthusiasm in the sekond year, when the troublesome "ph" will be replaced with "f". This will make words like "fotograf" 20% shorter.

In the 3rd year, publik akseptanse of the new spelling kan be ekspekted to reach the stage where more komplikated changes are possible. Governments will enkorage the removal of double letters, which have always ben a deterent to akurate speling. Also, al wil agre that the horible mes of the silent "e"s in the language is disgraseful, and they should go away.

By the fourth year, peopl wil be reseptiv to steps such as replasing "th" with "z" and "w" with "v". During ze fifz year, ze unesesary "o" kan be dropd from vords kontaining "ou" and similar changes vud of kors be aplid to ozer kombinations of leters.

After zis fifz yer, ve vil hav a reli sensibl riten styl. Zer vil be no mor trubl or difikultis and evrivun vil find it ezi to understand ech ozer. Ze drem vil finali kum tru! And zen world!

Oxford Dictionary:

mid 19th cent. (originally US): probably an abbreviation of orl korrect, humorous form of all correct, popularized as a slogan during President Van Buren's re-election campaign of 1840 in the US; his nickname Old Kinderhook (derived from his birthplace) provided the initials

AskOxford:

There have been numerous attempts to explain the emergence of this curious colloquial expression, which seems to have swept into popular use in the US during the mid-19th century. Most of them are undoubtedly pure speculation. It does not seem at all likely, from the linguistic and historical evidence, that it derives from the Scots expression 'och aye', the Greek ola kala ('it is good'), the Choctaw Indian oke or okeh ('it is so'), the French aux Cayes ('from Cayes', a port in Haiti with a reputation for good rum) or au quai ('to the quay', as supposedly used by French-speaking dockers), or the initials of a railway freight agent called Obediah Kelly who is said to have written them on lading documents he had checked.

The oldest written references to 'OK' result from its adoption as a slogan by the Democratic party during the American Presidential election of 1840. Their candidate, President Martin Van Buren, was nicknamed 'Old Kinderhook' (after his birthplace in New York State), and his supporters formed the 'OK Club'.

This undoubtedly helped to popularize the term (though it did not get President Van Buren re-elected!). During the late 1830s there had been a brief but widespread craze in the US for humorous misspellings, and the form orl korrekt which was among them could explain the initials 'OK'. Such a theory has been supported by more than one distinguished American scholar, and is given in many dictionaries, including Oxford dictionaries.

The only other theory with at least a degree of plausibility is that the term originated among Black slaves of West African origin, and represents a word meaning 'all right, yes indeed' in various West African languages. Unfortunately, historical evidence enabling the origin of this expression to be finally and firmly established may be hard to unearth.

I guess it's not material. You can include double quotes in the anchor text. Or you can exclude them together with the exclamation mark :)

green-eyed = jealous, envious