Every one of my in-laws (talk/talks) my ear off on the phone
talk/talks
No one (knows/know) the exact number of words in the English language
knows
Most of my friends (speak/speaks) English fluently
speak
A great number of my friends (have/has) sharp tongues
Have
A lot of people (go/goes) abroad to practice English
go
My students can't write without spell check. The majority (isn't/aren't) great spellers
aren't
A recent report indicated that about one fourth of American high school students (don't graduate/ doesn't graduate)
don't graduate
All fluent speakers (need/needs) to have an understanding of idiomatic language
need
Plenty of my friends (likes/like) to send each other text messages
like
Each person (finds/find) the level of formality he or she is comfortable with
finds
Every language (has/have) formal and less formal registers
has
A minority of American English speakers (understand/understands) Australian slang
Understand