Six weeks of training wear away the foul speech, double negatives and incorrect tenses.

FORBES: Silicon Valley's Prison Call Center

She is wearing sweats and a Howard T-shirt, and she tenses her forehead.

NEWYORKER: Miss Lora

Often tenses are left out of discussion, although everyone knows what is implied.

FORBES: Greg Mortenson Answers 60 Minutes Questions: A Tale of Two PDFs

Markers also found candidates used commas and capital letters randomly and were uncertain about the correct use of tenses, apostrophes and paragraphs.

BBC: Scottish exam markers find errors in basic English

When asked directly about hosting controversial objects on Thingiverse, Pettis tenses up.

FORBES: Inside Thingiverse, The Radically Open Website Powering The 3D Printing Movement

Mandarin has no tenses to indicate past or future.

BBC: A bullet train to nowhere

English past tense verbs have so many forms like swam, ate, read, let, brought, etc. compared to Japanese, where all past tenses end with -mashita, -mashita, -mashita, with virtually no exception.

FORBES: English - The Language of Global Business?