Learn Dutch: Werkt de nieuwe stofzuiger goed? - Does the new vacuum cleaner work well?

Stofzuiger is a compound noun made of stof (dust) and zuiger (sucker). Zuiger is formed by taking the stem of the verb zuigen (to suck) and adding the -er suffix. This transforms the verb into a noun representing the instrument performing the action. Literally, it translates to 'dust-sucker'.

Why do we use -er here instead of -aar or -der to make the instrument noun?

The -er suffix is the standard default for creating agent or instrument nouns from verbs. You usually only switch to -aar when the verb stem ends in an unstressed syllable like -el, -en, or -er (e.g., wandelen becomes wandelaar), and to -der when the verb stem ends in -r (e.g., huren becomes huurder). Since the stem of zuigen is zuig, we use the standard -er.

Since stofzuiger is a compound, how do I use its corresponding verb stofzuigen in a main clause?

This often trips learners up! Even though it looks like it should be a separable verb, stofzuigen is actually inseparable in standard Dutch. You say ik stofzuig (I vacuum), not ik zuig stof. This is because the verb stofzuigen was created after the noun stofzuiger already existed, a process known as back-formation.