Magma is red.
Subject + verb "to be" + adjective
Subject + adjective
Where there's just missing information, you can ask, in English:
What is love?
Interrogative adjective + subject + verb
and in Neutralus:
Amorus est quo? (lit. Love is what?)
Subject + verb + "quo"
It is raining.
"It" + verb "to be" + adjective or verb
Participle or adjective + infinitive of the verb "to be"