How to spot an intransitive verb?

How can i easily differentiate between a transitive and an intransitive verb? Are there any set of rule that set them apart or is it solely based upon the context of the sentence?

GB

There are transitive verbs, intransitive ones, and there are verbs that are of both types.

I play very well. Intransitive, because there is no object attached to the verb.
I play football.  football is the direct object of the verb, thus 'play' here is transitive.
I like you. 'you' is the object.
I fell off the three. The highlighted part is an advebial phrase, 'off' is the adverbial particle. "fall" here takes no object.

Transitive verbs take an object, intransitives do not.

No, I did not know the correct spelling

It's "tree". Do you pronounce it as "three"?

I'm not on your back. I was interested in knowing how you pronounce the word "tree". Many of my Spanish speaking students pronounce it as "three" in English. Often, they spell it that way too.