The problem is that grammar is somewhat tied to meaning here. The position of an adjective in a sentence depends on its role.
When used attributively (to describe a noun), as stated in other comments and answers, the adjective comes before the noun:
All navigable rivers are being patrolled.
If you say:
All rivers that are navigable are being patrolled. (Others are not)
This can become:
All rivers navigable are being patrolled.
At first glance this doesn't really seem to change the meaning since:
rivers that are navigable = navigable rivers
Edit: But...
When an adjective comes after the noun it describes (like in the 3rd example), it functions as a postpositive modifier. Changing the position of the adjective (relative to the noun it describes) may bring a slight difference in the meaning of the sentence (the meaning of the word itself does not change!). When used postpositively an adjective connotes an ephemeral quality, one that is present at the moment, but doesn't always have to be. On the other hand, the adjectives used attributively may express either an ephemeral or a permanent characteristic, depending on the context. The difference between attributive and postpositive use of an adjective is explained in more detail in (the middle of) this post and in the comments.
Only some adjectives can be used both attributively and postpositively (while retaining the same word meaning), and these are the ones ending in -able and -ible (such as navigable). (But not even all of those - see later: responsible).
To cover another aspect (this is where grammar kicks in again): if an adjective is used predicatively (in a pattern: subject + verb + object + complement (here an adjective)) it would be in a sentence like this:
Signalisation on the banks made rivers navigable. (Or something like that, I'm not really an expert on rivers).
The upcoming event made people excited.
The meaning of some adjectives (when used as modifiers) changes depending on whether they are used attributively or postpositively. Some examples are: concerned, responsible, present etc. Neither navigable nor excited are among those. Here the meaning of the word itself changes and the difference can be determined by checking the dictionary definitions.
There's a significant difference here. If you use the definite article the you're talking about specific textual delimiters used to block the site. Without the article you're simply stating how you're blocking the site (through the use of textual delimiters).
Allow me to clarify the difference through a simpler sentence:
- The cat often steals children's toys.
- The cat often steals the children's toys.
In the first sentence you say that the cat often steals toys that are normally used by children. The second sentence however, states that the cat often steals toys that belong to specific children that were either talked about earlier or are known in the context.
The difference in your sentence is the same. Are you talking about the use of textual delimiters in general? Then use the zero article. Are you talking about the use of specific textual delimiters? Then use the definite article the.
Best Answer
Seek for is not idiomatic English and is a contamination of to look for and to seek. You seek something or you seek to do something, but the preposition for is not normally used in combination with the verb seek. You could say:
Here is an example of seek + to infinitive:
In your second sentence, the adjective different should follow life, because from this one modifies different and not life. Therefore, you should attach it to the adjective instead of splitting the postmodifier into a pre- and postmodifier by putting life in between:
There is a difference in usage for pre- and postmodifiers. Premodifiers precede the main noun of your phrase and are normally not too long. Having a long premodifier makes it more difficult to read the phrase. Often, long modifiers are put after the main noun as a postmodifier (although in scientific writing you can still find long premodifiers).
In your example different from this one is a rather long phrase, which is why you should use it as a postmodifier rather than a premodifier. If you only use the adjective different, you can use that as a premodifier. Simple adjectives are often put in the premodifier and longer phrases, such as relative clauses, are used as postmodifiers.
So, in your phrase with skilled, avoid a long premodifier:
In any case, do not split your adjective from other phrases that are modifying it:
In the above sentence, skilled still modifies people, but in mathematics no longer modifies skilled. As a result, you're saying that in mathematics is the location where you will be looking for skilled people.
Both of your sentences with long premodifiers sound odd. If you have no postmodifier, don't put in a long premodifier. You could perhaps make your premodifier slightly longer if your postmodifier is already terribly long, but in general the premodifier restricts itself often to just some adjectives, except for scientific writing as I mentioned earlier:
Note how the premodifier more or less restricts itself to adjectives (and adverbs) while relative clauses, gerunds and other phrases often go in the postmodifier. In all four of the sentences above, the premodifier could be moved and used as a postmodifier whereas it would not really work the other way around.
Additionally, it sounds rather odd to mention from this one before you mention life.
In short, don't make your premodifier too long, it will not improve readability. Restrict it to mostly adjectives and perhaps adverbials modifying those adjectives. Longer phrases should go in the postmodifier.