In English, double consonants do not normally begin a common word, although some Welsh place names start with LL, as do Spanish words adopted into English. Dutch words provide some AA beginnings.
Examples:
A
aardvark, aardwolf
E
eerie
L
llama, llano, llanero
O
oodles, oops (oocyte, oogamous, oospore - biology)
addallassbeeboocooebbeggerrfeegeeillinnleeloomoooddoffpeeseeteetoozoo
What two words have the most letters in them?
antennachurchdecidedecodedeludederidedefiededitededucatedeligibleemblemeraseretiquettekayaklabiallegiblemagmarecaptureregisterrecorderreassurereorderreminderreporterrequirerestoreretirerevolversecludessenseseriessermonisesheathssheepishstartstemperatetenetthirteenththirtiethtomato
Some words that begin and end with the same letter and contain CA are:abracadabraacaciaacademiaalpacabicarbcarcinogenicdecaffeinateddecanteddecapoddecayeddedicateddefecateddesiccateddiscarddislocatedduplicatededucateencapsulateencaseequivocateeradicateescalateescapadeescapeescaroleevocativeexcavateexcommunicateexplicateextricatelackadaisicalliturgicallocallogicallogisticallyricalmacadamminicamnotificationnullificationscabiesscalesscallopstelecasttomcattoxicanttypecast
The anagram for the word "continued" is "unnoticed." The two words are spelled from the same set of letters. There are other phrases that use the same letters, such as "counted in" and "nice donut."
When two words have the same letters but in a different order, they are called anagrams.
Two different words with the same letters, like vein and vane is called a homonym. Another homonym is formed by the words great and grate.
anagrams
"Femme Fatale"
cruise ship
Aardvark, Oolong
The longest two words in the English language that are pronounced exactly the same and have no letters in common are "loaner" and "owner."
addallassbeeboocooebbeggerrfeegeeillinnleeloomoooddoffpeeseeteetoozoo
What two words have the most letters in them?
antennachurchdecidedecodedeludederidedefiededitededucatedeligibleemblemeraseretiquettekayaklabiallegiblemagmarecaptureregisterrecorderreassurereorderreminderreporterrequirerestoreretirerevolversecludessenseseriessermonisesheathssheepishstartstemperatetenetthirteenththirtiethtomato
Two that immediately spring to mind are bouquet and boulevard
Not always... There are chemical elements beginning with the same letter - for example Copper and Cobalt. However - every chemical symbol does consist of two letters.