There are many transliteration keys, the following is based on the popular Arabic to English dictionary Hans Wehr with slight amendments to reflect current modern usage, like šh instead of š for šhīn.

Transliteration of the Arabic alphabet:

Letter	Name	Transliteration
ء	hamza	ʼ
ا	alif	ā
ب	bā	b
ت	tā	t
ث	ṯhā	th (like thin)
ج	gīm	j
ح	ḥā	ḥ (breathy H like happy)
خ	ḵhā	ḵh (like loch)
د	dāl	d
ذ	ḏhāl	ḏh
ر	rā	r
ز	zāw	z
س	sīn	s
ش	šhīn	šh
ص	ṣād	ṣ (sword but less emphasis on the r)
ض	ḍād	ḍ (as above, ḍord)
ط	ṭāw	ṭ
ظ	ẓāw	ẓ
ع	ʽain	ʽ, ʽa, ʽe, ʽu
غ	ġain	ḡh
ف	fā	f
ق	qāf	q
ك	kāf	k
ل	lām	l
م	mīm	m
ن	nūn	n
ه	hāʼ	h
و	wāw	w, u, or ū
ي	yāʼ	y, i, or ī

• Hamza (ء) is represented as ʼ in the middle and at the end of a word. At the beginning of a word, it is not represented.
• The tāʼ marbūṭa (ة) is normally not represented, and words ending in it simply have a final -a. It is, however, represented with a t when it is the ending of the first noun of an iḍāfa and with an h when it appears after a long ā.
• Long vowels: ā ī ū i.e. aa, ee, oo
• Short vowels: fatḥa is represented as a, kasra as i and ḍamma as u.
• Wāw and yāʼ are represented as u and i after fatḥa: ʻain “eye”, yaum “day”.
• Non-standard Arabic consonants: p (پ), ž (ژ), g (گ)
• Alif maqṣūra (ى): ā
• Madda (آ): ā at the beginning of a word, ʼā in the middle or at the end
• A final yāʼ (ي), the nisba adjective ending, is represented as ī normally, but as īy when the ending contains the third consonant of the root. This difference is not written in Arabic.
• The definite article: The Arabic definite article الـ is represented as al- except where assimilation occurs ( sun and moon letters): al- + šhams is transliterated aš-šhams (The Sun). The a in al- is omitted after a final a (as in lamma šhamla l-qatīʻ “to round up the herd”) or changed to i after a feminine third person singular perfect verb form (as in kašhafat il-ḥarbu ʻan sāqin “war flared up”).