Alcohols alkylate to give ethers:  
When the alkylating agent is an alkyl halide, the conversion is called the Williamson ether synthesis.
Alcohols are also good alkylating agents in the presence of suitable acid catalysts.  For example, most methyl amines are prepared by alkylation of ammonia with methanol.  The alkylation of phenols is particularly straightforward since it is subject to fewer competing reactions.
:(with  as a spectator ion)
More complex alkylation of a alcohols and phenols involve ethoxylation.  Ethylene oxide is the alkylating group in this reaction.