an The word begins with a vowel.

an endoscope. +4

An endoscope. Because endoscope starts with e and that is a vowel.

An endoscope is the correct one hope you would have not forgotten the vowels [A E I O U]. So accordingly An is the apt one. Gotcha ?? Lovingly Maggge.

AN endoscope. +5 Scooter

The rule for determining the use of "a" or "an" is PHONETIC, not a spelling rule. This means it's based on the SOUND of the word. If the word SOUNDS like it starts with a vowel sound, then you use "an". If the word SOUNDS like it starts with a consonant sound, then you use "a". Thus, "hotel" uses "a", because the word begins with a consonant sound. And "hour" uses "an", even though it starts with a consonant like hotel, because the "h" is silent. So, to answer your question, you would properly say "an endoscope". Now, that said, I'm sure you'll have run across the phrase "an historic", which goes counter to this phonetic rule. "A historic" is more common, but both are sufficiently common to be considered correct. Nobody really knows why "an historic" is used...one theory is that some regional dialects may pronounce "historic" with a silent "h". Some words of three syllables or more that start with "h" are simply treated differently than the phonetic rule implies. You will NOT go wrong by strictly applying the phonetic rule, though. Any exceptions to this rule are very rare, and in any case are almost exclusively limited to the phrase "an historic". http://www.english-zone.com/grammar/a-anlessn.html http://www.betterwritingskills.com/tip-w005.html

an endoscope any word with sound startinf from a,e,i,o,u etc requires "an" for ex university spells as yuniversity so a university hour is spelt our so an hour

An endoscope.