The Conditional Mood

is expressed by the verb ending -us:

• mi kredus – I would believe, I should think
• Se mi estus sana, mi estus tre feliĉa. – If I were (was) well I would (should) be very happy.

Kvazaŭ

is used as a conjunction, normally followed by the conditional:

• Vi sidas tie kvazaŭ vi estus riĉulo. – You are sitting there as if you were a wealthy man.

It can also by used elliptically:

• Vi sidas tie kvazaŭ riĉulo. – You are sitting there as if rich.

The Suffix -ad

is used to make a verb form a noun:

• kanti – to sing
  • kantado – (the act of) singing
• suferi – to suffer
  • suferado – suffering

It also conveys the idea of continued or repeated action:

• rigardi – to look
  • rigardadi – to go on looking, to gaze
• demandi – to ask a question
  • demandadi – to keep asking questions
• informo – information
  • informado – publicity

The Suffix -ar

indicates a collection of objects viewed as a whole:

• arbo – tree
  • arbaro – wood, forest
• vagono – coach
  • vagonaro – train
• vorto – word
  • vortaro – dictionary

The Suffix -um

is a joker suffix, with no fixed meaning:

• plena – full
  • plenumi – to fulfil
• proksima – close
  • proksimume – approximately
• suno – sun
  • sunumi – to sunbath
• malvarmumi – to catch a cold