Understand that 'phrasal' involves a verb with an added preposition or adverb changing its meaning. The phrase 'turn down' means to reject, which is different from just 'turn'.
Pro Tip 2/3
Context Sensitive
'Phrasal' expressions can change meaning depending on the sentence context. 'Make up' can mean to reconcile or to invent a story, based on context.
Pro Tip 3/3
Multiple Meanings
Some 'phrasal' verbs have several meanings, making them tricky to use correctly. 'Take off' can mean to remove clothing, or a plane starting to fly.