Like can be used as a verb or a preposition.
We like the proposal.
[verb]
Lenticular clouds can look like flying
saucers.
[preposition]
Do not use like as an adjective, an interjection, or a conjunction.
We put like 15 drops of the compound into
the fuel mixture.
[adjective]
We put about 15 drops of the compound into
the fuel mixture.
They said, like, they would arrive at 9 for
the meeting.
[interjection]
They said they would arrive at 9 for the meeting.
We feel like the consultant is ignoring our
concerns.
[conjunction]
We feel that the consultant is ignoring our
concerns.