In Plural words^x, Possessives^x, Pronouns^x

No. A 'thank you' is a colloquial compound noun, like lounge room or room heater, and the 's' in 'thank yous' signifies the plural, so no apostrophe is used.Apostrophes are used to express possession e.g. Bob's car; or to indicate some letters have been omitted in a...

Apostrophe ( ' ) The apostrophe is used when leaving out a letter or number in a contraction, e.g. can't, wouldn't. The apostrophe is used for omitted letters, e.g. rock 'n' roll, and for omitted numbers, e.g. the class of '72, the '20s. The apostrophe is used for plurals of letter...