Learn Interlingue - Lesson 5

The degrees of comparison

| bon | plu bon | max bon |
| good | more good | most good |

| bell | minu bell | minim bell |
| beautiful | less beautiful | least beautiful |

Word derivation

In word derivation (making new words by changing some form of it), Occidental accepts both the principle of direct and indirect derivation. Direct derivation is limited to certain cases which are indicated in the complete list of affixes below. For direct derivation we must apply the three rules of the Wahl. To form nouns from verbal roots we detach the infinitive -r or -e/r [vid, vid-e/r] to obtain the perfect stem.

Rule 1: If, after removing the grammatical ending [-r, -e/r] the stem ends in a vowel, add -t or change -y into -t

| crea/r | crea/t | crea/t/or |
| atiny-e/r | atin/t | atin/t/ion |

Rule 2: If the final consonant of the stem should be either d or r, the letters are changed into -s [decide/r, deci/s, deci/s/ion].

Rule 3: In all other cases, except those especially cited below, the removal of the infinitive -r (or -er gives the required perfect stem [duct/e/r, duct-, duct/ion].

The six exceptions are

| cede/r | perfect stem cess- |
| sede/r | sess- |
| move/r | mot- |
| tene/r | tent- |
| verte/r | vers- |
| veni/r | vent- |

To form verbs from nouns and adjectives, we remove the endings and obtain the perfect stem. By adding -r or -er we will obtain, in most cases, the verb [decora/t/ion, decora/t, decora/r].