You use a. Use an only with words that start with a vowel sound.
A word that starts with s cannot start with a vowel sound, unless the s is actually pronounced like the name of the letter, which is not common. For example, you would say an S-hook, because that would be pronounced an ess-hook. However, for "normal" words that start with s, the article a is correct, as in a serious problem or a sock.
Use "an" before words that start with a vowel sound, including the letter "s" when it sounds like a vowel such as in "honor" or "hour." Use "a" before words that begin with a consonant sound.
The word that is a synonym of "look hard" starting with S is "scrutinize."
One word that starts with "s" and ends with "n" is "salmon."
"Spider" is a two-syllable word starting with "s."
It depends on how the "h" word is pronounced. Use "a" before words where the "h" is pronounced as a consonant sound (e.g., "a house"). Use "an" before words where the "h" is silent and the word is pronounced starting with a vowel sound (e.g., "an hour").
s' is used as an apostrophe for a word that refers to plural form, for example saying The girls' toys. In this instance it refers to the toys of more than one girl. You would also use s' for names ending with an s, such as Tess' toys. 's is used as an apostrophe for a word that refers to singular form, for example saying The girl's toys. This refers to the toys of just one girl. You would also use 's with names such as Tom's toys
The word that is a synonym of "look hard" starting with S is "scrutinize."
Seta is a 4-letter word for hair or bristle starting with S.
Stab -- an idiomatic use, as in, "He made a stab at getting the painting done."
what word starting with s is a synonym for technology? playful
Start
Santa
star
so
scoundrel
screwdriver
spotless
set