I am actually quite alarmed at how many posts there are claiming that grammar isn't important and that you should forget everything about grammar and start speaking instead.

While I can't fault the person who first stated this, I'm not sure that's exactly what they mean.

Being overly strict about grammatical correctness will not help you be confident in speaking, because you will be too critical about what you are going to say, and end up not saying anything instead. In this case, it will be better if you stop worrying so much about grammar.

However, if it leads to major grammatical mistakes that, sometimes, take away the meaning of the sentence, I think it should be made important.

There are some mistakes that you can overlook when you speak, but when you get basic grammar wrong, it will raise eyebrows. For example, you say: I eat noodles yesterday. People will look at you strangely, but they will understand what you are saying, nevertheless.

However, when something like this is said: "We will much more something"... I doubt anyone aside from the speaker will understand what is being said. I myself, for the life of me, can't figure out what it is supposed to mean. I have come across similar sentences, in which even when I try translating it back to Indonesian (word-by-word too!), I still can't figure out what they're trying to say.

In this case, yes, grammar is very important!

While it is good that you are learning a lot of words, and especially big words, there really is no need to use them as many times as you can. Big words are more context-specific and the chance of making a mistake in using it is bigger, and all it will do is show people you don't actually know the true definition of the word and how it should be used. For example, you just learned the word idiosyncratic (which, when I tried translating in sederet.com is translated as "aneh, istimewa"). So, with that knowledge in mind, you proceed to think of it as a synonym of "strange" or "special". Then you come across a peculiar event, and when you want to tell it to your friends, you say it's an "idiosyncratic event". They will probably look at you strangely (and not in an idiosyncratic manner either!), because that word, basically means "quirk", that is, a peculiar manner of thought or behaviour specific to an individual.

Keep everything you say simple but clear.

Also, try not to use big words in simple phrases. For example, you have just learned the word 'cacophony', which is, essentially, the same as noise. However, should you say, when you hear a loud noise, "What's that cacophony?" you will probably get strange looks instead of looks of awe.

Edit: keep everything simple. It leaves little room for error and misunderstanding. I don't know what's with people and the apparent need to use big or complicated words instead of simple and straightforward words. Unless you're writing a letter to an important person like the prime minister, there really is no need to be formal and complicated.

A lot of writers are strict on variety, as in, they will not use the same word twice in a paragraph, so they usually find a synonym for that. However, what we have to realise is that every synonym has their own meaning and context, and sometimes you can't blindly use a word to replace another, especially if you use a thesaurus to find it without consulting the context first. This is a point I make a lot of times: consult the context first.

If you ask someone who had had their writing picked at by me, they might say that most of the time I say the mistake lies with the diction--the choice of words.

For example, the word bad is synonymous with atrocious. However, bad has a milder connotation. You can say someone is a bad person, and not many will be affected. But if you say someone is cruel, a lot of people will stay away from that certain someone.

In the same way, if there is someone who looks bad, and you tell them that they look bad, they'll probably get offended and refuse to talk to you. But if you tell them they look atrocious, you might get a punch in the face.

Some words have the same translation from English to Indonesian, and there might be mistakes in choosing the right word due to this.

For example, someone once said this to me: during you have the will

I stared at the sentence for a few seconds trying to comprehend what was being said. Please note that we were talking about me waiting for my next semester and not really looking forward to it.

I then realised that they meant "selama kau punya keinginan". See the mistake there? During indeed is translated into "selama", but it is not appropriate in this context

Also, word-by-word translations are really awkward. My friend once tried translating "good morning to you" with Google Translate, and guess what he got: "pagi yang baik untuk anda". Yes. Awkward.

You will find there are contexts that require different word, although the general meaning is the same. An example I just came across is the usage of the word 'landmark' and 'milestone'.

Both words are used to indicate reference point, but they are different. Landmark implies a concrete object, something that can be seen. Milestone refers to an abstract object, something that cannot be seen.

For example, if you're asking someone for directions, they will tell you to use buildings or statues or anything, really, as reference points. These are 'landmarks'. This word also has other definitions, but for the sake of the example I will only discuss this particular definition.

But if you are to ask someone about their education so far, their graduations from primary school, junior high, senior high, etc are considered 'milestones'.