• ofline,
• offilne,
• offlline,
• iff-line,
• kff-line,
• lff-line,
• pff-line,
• 0ff-line,
• 9ff-line,
• odf-line,
• ocf-line,
• ovf-line,
• ogf-line,
• otf-line,
• orf-line,
• ofd-line,
• ofc-line,
• ofv-line,
• ofg-line,
• oft-line

The adjective form of the word "off-line" is "offline".

The plural form of "off-line" is "off-lines".

The singular form of the word "off-line" is "off-line". The word does not change in singular form because it is an adjective that describes something that is not connected or not online.