Setting this to true is essential for languages such as German which allow for compound words. For example: if the word is "thesewordsarejoined" when the property is set to "False" the word would be marked as misspelled. But when set to "True" the word would be marked as spelled correctly. However, if one of the words inside of the compound word was misspelled, the whole word would be marked as misspelled.
Setting this to true will degrade lookup performance by a maximum of approximately 100[1-1/n] percent (where n is the number of letters in the word) for misspelt words.
There is no performance degredation for correctly spelt words.
On average for texts with mostly correctly spelt words the performance degredation for the Check method is roughly 25%.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2