• 火(fire)
• 某(something; a certain thing)

Coal is a fuel extracted from the earth's interior that burns into fire.

• 隹(short-tailed bird)
• 灬(fire (base form))

A bird caught by fire burning underneath gets scorched, which is the meaning of the character 焦.

• 氵(water; liquid)
• 由(from; due to; oil (phonetic))

Oil is a liquid that flows from a natural source.

• 火(fire)
• 某(something; a certain thing)

Coal is a fuel extracted from the earth's interior that burns into fire.

• 隹(short-tailed bird)
• 灬(fire (base form))

A bird caught by fire burning underneath gets scorched, which is the meaning of the character 焦.

• 氵(water; liquid)
• 由(from; due to; oil (phonetic))

Oil is a liquid that flows from a natural source.