Have you ever run a 10 km marathon?

Running is an increasingly popular hobby in India as people get more health-conscious and realise that physical exercise is as important as a good diet. And for those who are competitive, or those who just like the thrill of running with hundreds of other people, there are many road races to choose from, at least in the big cities. You can choose from among a range of distances to run, depending on your ability, with the most common being 5 km (or 5K, as they usually say), 10 km, half marathon and marathon. 

But, what is a 10 km marathon that I sometimes read about, like in the following tweets?

Sh Sanjeeva Kumar, AS& DG #NACO with participants running for 10k marathon at Jawahar Lal Nehru stadium, for children living with #HIV. He flagged off the marathon along with MP, #RajyaSabha Sh @sachin_rt. pic.twitter.com/LUv4RTrutz

— Ministry of Health (@MoHFW_INDIA) February 25, 2018

The fine and gorgeous @macynyman, actress and daughter to Andy, is running a 10k marathon for cancer research. In case you’re feeling even a bit generous: https://t.co/wMAUgigwFC

— Derren Brown (@DerrenBrown) April 16, 2018

We'd like to say a huge "Thank you!" to Danny Burkhill who ran the Sheffield 10k Marathon (in a panda head costume) and raised a fantastic £83.27 for us. We really appreciate your support Danny. <3 :D #Sheffield pic.twitter.com/f4oBSNSwjx

— RSPCA Sheffield (@RSPCASheffield) November 4, 2018

Over 1500 enthusiastic Bengalureans from all age groups participated in the 5k and 10K marathon. The run was organised to create an awareness on importance of Education and fitness.#RunBengaluru#RunToEducate pic.twitter.com/m7LidsSTbK

— NEWS9 (@NEWS9TWEETS) December 2, 2018

#XAthon, a 10K marathon where the amount raised through registrations was donated for a cause

More - https://t.co/DyRcr21L5p#Xpressions17 pic.twitter.com/J0V7fet8uZ

— XIMB (@ximbee) October 16, 2017

Vicky Vantoch is a amazing woman. She ran a 10k marathon yesterday. Shes not only incredibly smart but she is a great athlete

— ElizabethO #BeAMisha (@eorozco2720) October 8, 2017

Some people seem to think that a road race of any distance is a marathon. They are mistaken. Only a race measuring 42.195 km is called a marathon and, not surprisingly, a half marathon covers half that distance: 21.0975 km. Hence, a 10K marathon makes no sense.

How do you use your pronouns?

How do you use your pronouns?#plainlanguagehttps://t.co/0RllqcSkVU

— plainlanguage.gov (@govplainlang) April 16, 2018

Do you know the meaning of #Lenovo ? Here's a fascinating etymology coming your way!#EtymologyEducation is a fantastic way to become the best student that you can.
Click here to study etymology with Logophilia: https://t.co/vZcjHmxaTA.
2018 © Logophilia Education Pvt. Ltd. pic.twitter.com/aT9xhjNTkr

— Logo+philia (@Logophilia_Edu) April 16, 2018

You might have heard that you have to avoid them, but what actually is a dangling participle? https://t.co/CE2A26RthJ

— Oxford Dictionaries (@OxfordWords) April 6, 2018

Do you know the meaning of #Panasonic ? Here's a fascinating etymology coming your way!#EtymologyEducation is a fantastic way to become the best student that you can.
Click here to study etymology with Logophilia: https://t.co/vZcjHmfA22.
2018 © Logophilia Education Pvt. Ltd. pic.twitter.com/dS9B1hFBLC

— Logo+philia (@Logophilia_Edu) April 5, 2018

Unchartered waters

Before the era of aviation, explorers and traders travelled the world by sea. They were aided by charts -- in other words, maps. Hence, regions for which charts were not available were uncharted waters. Uncharted waters and uncharted territory are used metaphorically these days to refer to new, unprecedented situations.

However, many people mistakenly write unchartered instead. Unchartered means not having a charter or written constitution. Take a look at the examples below:

Colombia in Unchartered Territory With Peace Deal's Defeat https://t.co/f5ByDOxden

— Llamma Lane (@llammalane) 3 de octubre de 2016

We are living in unchartered waters in #politics, says Miliband #tfwa #TFWA2016

— DFNI Magazine (@DFNI) 3 de octubre de 2016

At the New York HIT Summit, Diving into Unchartered Cybersecurity Waters | Healthcare Informatics Magazine https://t.co/utylXgreLs

— Luis Saldana (@lsaldanamd) 28 de septiembre de 2016

Interesting tweets - 2

"Lay" or "lie"? @GrammarGirl clears up any confusion: https://t.co/tJ47CVJIDV #grammar

— AP for Students (@APforStudents) September 16, 2016

Prone:👇 (facing downward)
Supine: 👆 (facing upward)
Prostrate:😲 (lying flat; overcome)https://t.co/WijShiAghF

— Merriam-Webster (@MerriamWebster) September 22, 2016

.@mzinshteyn Eh, that's fine. https://t.co/i8114W72Rt

— Merriam-Webster (@MerriamWebster) September 21, 2016

Few reasonable people still object to 'since' used to mean "because." 'As' might ruffle some feathers, however. https://t.co/lp7XhqIfN0

— Merriam-Webster (@MerriamWebster) September 20, 2016

Rest assured

According to Cambridge Dictionary, rest assured means to be certain that something will happen and gives this example: You can rest assured that you're going to get a good deal.

Quite often, however, I have seen it used with a be before it, like in the following examples:

• It may sound quite amazing and perhaps unbelievable, but you can be rest assured that what you're about to read is completely true.
• By choosing us you can be rest assured that your facility, project...
• ...you can be rest assured you have full rights to use all images...

This is not correct.

The rest in rest assured is a verb which means to relax, to not worry. You'll understand the expression better if you imagine a comma after rest. So you could paraphrase the first example as

...but you can rest, assured in the knowledge that what you're about to read is completely true. 

 Now you can easily see why be rest assured doesn't make sense.