'We cheer each other on before I depart.' - What does 'on' mean?

Question

I'm not a native-speaker; sometimes prepositions (or adverbs) are tricky for non-native speakers.

'We cheer each other on before I depart.'

https://www.youtube.com/watch?v=fgxCjetxgfU

(look at 2:10)

In this sentence, I don't know what does 'on' mean? I understand what 'on' means in these sentences:

There's a mark on your skirt.
Put your coat on.

But when we use 'We cheer each other on'... What nuance of meaning of the word 'on' is here?

Is it possible to omit 'on'?

'We cheer each other before I depart.' (Is this sentence correct?)

Would it still be the same meaning? Why does first sentence have 'on'? And could you tell me some example sentences with this meaning of 'on' in them?

Answer 1

"Cheer on" is a phrasal verb. "On" does not function as a preposition in this sentence, instead it is the "particle", part of the phrasal verb.

There are a great number of phrasal verbs in English, and unfortunately there's no great "trick" for knowing them, it's just a matter of learning them as vocabulary.

The meanings of "cheer somebody" and "cheer somebody on" can both mean "encourage with shouts and applause", but "cheer on" is more common. "Cheer somebody" can also mean "make them feel happy" but "cheer on" cannot. There are many phrasal verbs in English where the meaning is much further from the base verb.