Grammatically speaking, then is used as an adverb or adjective, while than is used as a conjunction or preposition.

harboring, harbouring, sheltering, hiding, taking refuge, taking shelter, holing up, seeking sanctuary, taking cover, finding refuge, seeking protection, seeking refuge, concealing yourself, vanishing, disappearing, accommodating, housing, lodging, boarding, quartering, domiciling, bunking, camping, roofing, rooming.

friendlily. (rare) In a friendly manner; like a friend; warmly; kindly.

abnormally absentmindedly accidentally actually adventurously afterwards almost always annually anxiously arrogantly awkwardly bashfully beautifully bitterly bleakly blindly blissfully boastfully boldly bravely briefly brightly briskly broadly busily calmly carefully carelessly cautiously certainly cheerfully clearly …

Because of their distinctive endings, these adverbs are known as -LY ADVERBS. However, by no means all adverbs end in -ly. Note also that some adjectives also end in -ly, including costly, deadly, friendly, kindly, likely, lively, manly, and timely.

Here is a list of adverbs that don’t end in -ly:

• afterward.
• already.
• almost.
• back.
• better.
• best.
• even.
• far.

If the adverb is placed before or after the main verb, it modifies only that verb….Examples.

An adverb is a word that modifies (describes) a verb (he sings loudly), an adjective (very tall), another adverb (ended too quickly), or even a whole sentence (Fortunately, I had brought an umbrella). Adverbs often end in -ly, but some (such as fast) look exactly the same as their adjective counterparts.

When modifying an entire sentence, adverbs can be placed in four positions:

1. at the beginning;
2. at the end;
3. after the verb to be and all auxiliary verbs: can, may, will, must, shall, and have, when have is used as an auxiliary (for example in I have been in Spain twice);
4. before all the other verbs.

FIGURE 2.1 Each centimeter contains 10 millimeters. The base unit of volume in the SI system is the cubic meter (m3)….

Alternative Titles: centimeter, cm. Centimetre (cm), also spelled centimeter, unit of length equal to 0.01 metre in the metric system and the equivalent of 0.3937 inch.

The centimeter can be written as cm. While calculating the surface area of an object, the unit of measurement becomes cm2. While measuring the volume of an object, the unit of measurement becomes cm3.

The gallon is a unit of measurement for volume and fluid capacity in both the US customary units and the British imperial systems of measurement….

Some commonly used non-SI units