Some Commonly Encountered Alkyl and Aryl Groups
Group	Name	Group	Name
CH3 —	Methyl	CH3CH2 —	Ethyl
CH3CH2CH2 —	Propyl or n-propyl	(CH3)2CH —	1-Methylethyl or isopropyl
CH3CH2CH2CH2 —	Butyl or n-butyl	| CH3CH2CH2CH3	1-Methylpropyl or sec-butyl
(CH3)3C —	1,1-Dimethylethyl or tert-butyl	(CH3)2CHCH2 —	2-Methylpropyl or isobutyl
(CH3)3CCH2 —	2,2-Dimethylpropyl or neopentyl	CH2=CH —	Ethenyl or vinyl
CH2=CHCH2 —	2-Propenyl or allyl	| CH2=CCH3	1-Methylvinyl or isopropenyl
| CH3C=O	Ethanoyl or acetyl (derived from a carboxylic acid)		Phenyl (C6H5 — )
	Phenylmethyl or benzyl (C6H5-CH2 — )		Benzenecarbonyl or benzoyl (C6H5-CO — )
The groups shown above, are commonly encountered in organic compounds.  You should be familiar with all of these groups, since compounds we encounter often contain them.  Group names are systematic, but learning the rules for these group names takes some time.