[zoneoni]

Usually when your speaking to children, your given more room with your English since they are for the most part silly by nature. They love little onomatopoeias like "VROOM" or "BANG!" and use it during their everyday play-styles. For formal writing using "really, really, really" is considered informal writing even when writing letters to parents would strike an odd eyebrow. If these were letter's to children it would pass as excusable but if the use of the letter was to teach then that too might not be a good idea.

Usually if you wanted to focus something or emphasize a feeling like let's take love for example. There are generally two ways to show greater emotion then using an extension like really or more, etc; would the use of smilies or metaphors. These are basic ways of showing stronger expression, they can become more complex and intricate.

Simile:
For example:
If you were speaking to a child and wanting to show an expression of love in Simile form, it would be something like this.

Jerry, your such a good kid. I love you as much as your mother does.

This sentence is describing your love for Jerry just as much as his mother does. It's a strong sentence and says a lot. For this explicit case though, putting the idea in which the cause lies in is important. "Jerry, your such a good kid is just such a reference. It implies that because he is a good kid (well-behaved and good manners), you have a level of affection for him. If this sentence was not there then it takes on a slightly different meaning, you would be implying that you may or may not abduct to take him home, hehe, something along those lines.

Similes for the most part have the following structure when in use.

Part A as Part B
The as can be replaced with either like or as.

Example 2:
The only time I have felt this way is like the time when I drew breath for the very first time.

This sentence is a little bit more advance since it is referring to a past experience of someone's life, depending on that experience this could be a good compliment to said person's well-being or a sign of frustration/anger/remorse etc.

Metaphors are much more complex and their is no type of word that would help you identify one unless you read the sentence. By reading a sentence fully you would be able to see if it was a metaphor or not.

Metaphor is usually when a subject takes on the properties of a 2nd subject. The 2nd subject usually being some sort of level in extremity.

Example 1:
Terry flew at full speed into the clouds his feathers wrapping around him, as his friends watched in astonishment.

This metaphor is about Terry as he is being compared to some sort of flying animal, most likely a bird since feathers play a role in describing the state in which he is in. However you can see that this sentence has an as but is not a simile. This is because this as is a time reference the comma in front of the as let's the reader know that he should treat the first part of the sentence before the comma as a separate sentence from the rest of the sentence after the comma. There are many many different types of metaphors which are all different and use different properties, similes would be the easiest way to show greater emotion and inference.