• erth,
• ker,
• wer,
• fer,
• ez,
• ery,
• gr,
• iery,
• zeor,
• vr,
• erm,
• wr,
• eri,
• erea,
• ser,
• ver,
• xr,
• eirc,
• ey,
• eyr

• era,
• eerie,
• ar,
• -ar,
• RR,
• per,
• -er,
• re-,
• err,
• e,
• ear,
• -ey,
• e-,
• eery,
• R,
• e's,
• -or,
• -r,
• erie,
• Ere,
• -ed,
• Her,
• Per-,
• or.

The adjective form of the word "er" is "earlier".

The plural form of "er" is "ers"

The singular form of the word "er" does not exist. It is already in its singular form. It is a noun suffix used to denote a person or thing that performs a particular action or has a particular quality. Examples include baker, teacher, writer, etc.