Further vs. Farther, & Like vs. As

To continue the confusing words train, let's talk about Further versus Farther and Like versus As! 

The TARDIS can take you anywhere in time and space!

But does it go further OR farther when it goes? Here's the basics:

Further with a U means figurative distance, and Farther with an A means physical distance.  Not too bad as grammar rules go.   

The Daleks went further into the "magic trash can" aesthetic than the Cybermen.(Figurative distance)

In the Doctor Who episode, "Listen," the Doctor takes the TARDIS farther than ever before: they go to the end of the universe. (Physical distance)

And then it gets wibbly-wobbly.

Of course, there are exceptions, or in this case--there's ambiguity. Sometimes, further and farther are interchangeable. 

If it's difficult to tell which kind of distance you're talking about--figurative or physical--then you can use either one. 

Typically, if I can't decide, I use further with a U because if it's not obviously physical distance (I drove farther), then it's probably a little abstract (I read further), which leans towards figurative.  If I say, "I read further," I could be referring to my physical distance along a page count, or I could be referring to my figurative place in the storyline. Since it's not immediately clear, I choose to use further as it covers more possibilities. 

Farther with an A strictly speaks to physical distance, so it's more of a commitment to a quantifiable thing when used. 

Furthermore, distance in the TARDIS can get timey-wimey.

Furthermore basically means "in addition." You wouldn't really say "further into that idea," but you do say "Furthermore, I love Firefly." This means that in addition to loving Doctor Who, I also love Firefly.  

Furthermore, Star Wars is the best.

There is no such a thing as farthermore with an A, so that's easy! 

Mary Poppins' suitcase was like a TARDIS!

It was bigger on the inside, but as far as we know, that fancy carpetbag didn't travel through all of space and time...though I won't argue definitively that wasn't a possibility.  (Because clearly Mary Poppins had access to other dimensions, plus she had a flying umbrella...but I digress.)

Like versus As

We're tip toeing on formal grammar territory now! What's the difference between LIKE andAS?

The basic rule is that LIKE is preposition and AS is a conjunction (FANBOYS). 

Prepositions establish location or relationships and are usually followed by a noun: The TARDIS is across the street. Amy Pond is among the Doctor's list of  time-travelling companions.

Conjunctions connect phrases and clauses, and they're usually followed by a verb: We're going to Mars and I'm taking my sonic screwdriver! Rose Tyler was marooned in a parallel universe, but she found a way back to the original one. 

So basically, use LIKE when there's no verb to follow and AS when there is a verb. 

LIKE will connect simpler statements to show a relationship (spatially or associatively), whileAS will express something more complex by combining two phrases.

Amy Pond is like a superhero! (LIKE followed by a noun)

It's as if Clara Oswald was always meant to save the Doctor. (AS followed by a clause with a verb)

There isn't another show quite like Doctor Who.

Watching Doctor Who, it's as though the writers read Peter Pan and then translated it as a guilt-free escapist fantasy for adults. 

AS THOUGH follows the same rules as AS IF. 

Mignon Fogarty points out that some grammarians will argue that "as though" applies to more plausible ideas, while "as if" goes with more fantastical ones. There's no hard and fast rule on this, though, and by most standards these phrases are considered interchangeable. 

Wait one second! 

We often hear statements using LIKE instead of AS, and no grammar nerds started crying, so why aren't we saying they're interchangeable?

In formal writing this  sentence would be considered wrong: It's like Donna Noble was the Doctor. 

It's wrong (it is!) because LIKE in this instance is occupying the place of a conjunction, and it's NOT a conjunction. 

It's as if Donna Noble was the Doctor. (Yay!) 

So, to be safe, when writing essays, always double check LIKE and AS to make sure LIKE is still a preposition and AS is still a conjunction. If you have a clause (a statement containing a verb) after LIKE, then you need to fix it. 

Resources:

 Fogarty, Mignon. "'Further' Versus 'Farther.'" Grammar Girl's Quick and Dirty Tips. Last Modified April 22, 2010. Accessed February 26, 2016. http://www.quickanddirtytips.com/education/grammar/further-versus-farther?page=1 

-----------. "What I like about you: Like Versus As." Grammar Girl's Quick and Dirty Tips for Better Writing. New York: St. Martin's Press, 2008. 

Simmons, Robin L. "The Coordinating Conjunction." Grammar Bytes! Accessed February 26, 2016. http://www.chompchomp.com/terms/coordinatingconjunction.htm

------------. "The Preposition." Grammar Bytes! Accessed February 26, 2016. http://www.chompchomp.com/terms/preposition.htm