IN- is among the most common English prefixes, meaning "into" or "not": INCLUDE, INCREASE, INDEED, INDUSTRY, INFLUENCE, INSIDE, INSTEAD, INTEREST, and INTO. IN- words are the backbone of both spoken and written English.
INFIX (15 pts) and INDEX (13 pts) are excellent 5-letter IN words combining the prefix with rare letters. INVOKE (13 pts) and INFLUX (16 pts) are strong 6-letter plays. IN- bingos like INSPIRE and INVOLVE are frequent rack-clearing plays.
High-value word starts for Scrabble, Wordle, and crosswords