From Laura K. Lawless,
Your Guide to French Language.
The French word comme can be a conjunction, adverb, or part of an adverbial phrase and is one of the most common French words
Comme as a conjunction
Comme is a French subordinating conjunction meaning "as" or "since":
Il est arrivé comme je commençais à manger
He arrived as I was starting to eat
Comme il n'est pas là, je vais le faire
Since he's not here, I'm going to do it
Comme is commonly used in comparisons to mean "like" or "as":
Pensent-ils comme nous ?
Do they think like/as we do?
C'est une excuse comme une autre
It's as good an excuse as any
Comme as an exclamative adverb
As an exclamative adverb, comme means "how" or "so":
Comme tu es grand !
You're so tall!
Comme il fait beau !
How beautiful the weather is!
Comme + adjective
Comme plus an adjective means that something/someone seems to be that adjective:
Il était comme fou
He was acting crazy
Elle est comme désorientée
She seems bewildered
Comme tout
An adjective followed by comme tout means "so (adjective)" or "as (adjective) as can be":
C'est facile comme tout
It's as easy as can be
Il est sympa comme tout
He's so nice
Comme si
Comme si means "as if/though":
Il m'a parlé comme si rien ne s'était passé
He talked to me as if nothing had happened
Ce n'est pas comme si je suis riche !
It's not as though I'm rich!
Expressions with Comme
Comme is found in a number of common French expressions:
comme cela/ça - (just) like that, that way; (informal) great, terrific
comme ci, comme ça - so-so, fair
comme il faut - properly
comme il vous plaira - as you wish
comme les autres - ordinary, everyday
comme on dit - as they say
comme par hasard - coincidentally
comme qui dirait - (informal) as you might say, what you might think is/was
comme quoi - to the effect that, which goes to show that
comme tout le monde - normally, like everyone else
juste comme - just/right as