Fiat lux: Genesis 1:3-5

Genesis 1:3: fiat lux

Dixitque Deus: Fiat lux. Et facta est lux.

And God said: Let there be light. And light was made. (Genesis 1:3)

Three pieces of grammar in eight words:

-que means and, glued to the end of the word it joins. When a word ending in -que is not in the dictionary, chop off the -que and look up the rest. Beware words that only look like it: itaque, therefore, and quisque, each, are words in their own right.

Fiat is a jussive subjunctive: the subjunctive on its own in a main clause, giving an order to someone who is not being spoken to. Fio serves as the passive of facio. Lux is nominative, not accusative: nothing here has an object.

Facta est is perfect passive. The participle agrees like an adjective, so it is feminine to match lux; and Latin builds this past tense with the present of sum, so facta est means was made, not is made:

More in the passive voice and the subjunctive.

Genesis 1:4-5: quod, and naming

Et vidit Deus lucem quod esset bona: et divisit lucem a tenebris. Appellavitque lucem Diem, et tenebras Noctem: factumque est vespere et mane, dies unus.

And God saw the light, that it was good: and he divided the light from the darkness. And he called the light Day, and the darkness Night: and there was evening and morning, day one. (Genesis 1:4-5)

This is the sentence that matters. Cicero reports what someone saw with the accusative and infinitive; the Vulgate uses quod plus a subjunctive:

Esset is the imperfect subjunctive of sum, past because vidit is past; bona is feminine to match the light. This quod does the job of French and Spanish que and English that: Romance grammar being assembled out of Latin parts. The classical way is in indirect statement.

Three more things in verses 4-5:

• A tenebris is a plus the ablative of separation: from the darkness. A before a consonant, ab before a vowel or h.
• Appellavit takes two accusatives: lucem Diem, the light (what he named) Day (the name). English does the same: he called the light Day.
• Dies unus, day one, not the first day: the Hebrew says one, and Jerome kept it.