Aunque su uso puede confundirse en la escritura, es en realidad muy sencillo diferenciar entre sus usos.

A ver

Se trata en realidad de la preposición "a" y el infinitivo verbal "ver":

Quote:—A ver, ¿has hecho lo que te dije?
—Vete a ver qué nota te han puesto.
—A ver como te va con tu madre con esas notas.

Haber

Se trata de un verbo o un sustantivo. Como verbo, haber se usa como auxiliar, seguido de un participio:

Quote:—Tiene que haber sucedido algo.
—Sigo sin haber entendido lo que ha pasado.

También se emplea como infinitivo del verbo impersonal que denota la presencia o existencia de lo designado por el sustantivo que lo acompaña:

Quote:—Parece haber un chico esperándote en la puerta.
—Tiene que haber deberes pendientes.

Fuente: RAE

Ayeba.fr wrote: Quand j’étais petit, j’adorais le cirque, et ce que j’aimais par-dessus tout, au cirque, c’étaient les animaux. L’éléphant en particulier me fascinait; comme je l’appris par la suite, c’était l’animal préféré de tous les enfants. Pendant son numéro, l’énorme bête exhibait un poids, une taille et une force extraordinaires… Mais tout de suite après et jusqu’à la représentation suivante, l’éléphant restait toujours attaché à un petit pieu fiché en terre, par une chaîne qui retenait une de ses pattes prisonnière. Mais ce pieu n’était qu’un minuscule morceau de bois à peine enfoncé de quelques centimètres dans le sol. Et bien que la chaîne fût épaisse et résistante, il me semblait évident qu’un animal capable de déraciner un arbre devrait facilement pouvoir se libérer et s’en aller. Le mystère reste entier à mes yeux.

« Alors, qu’est ce qui le retient ? Pourquoi ne s’échappe t-il pas ? »

À cinq ou six ans, j’avais encore une confiance absolue dans la science des adultes. J’interrogeai donc un maître, un père ou un oncle sur le mystère du pachyderme. L’un d’eux m’expliqua que l’éléphant ne s’échappait pas parce qu’il était dressé. Je posais alors la question qui tombe sous le sens:

« S’il est dressé, pourquoi l’enchaîne-t-on ? »

Je ne me rappelle pas qu’on m’ait fait une réponse cohérente. Le temps passant, j’oubliai le mystère de l’éléphant et de son pieu, ne m’en souvenant que lorsque je rencontrais d’autres personnes qui un jour, elles aussi, s’étaient posé la même question.

Il y a quelques années, j’eus la chance de tomber sur quelqu’un d’assez savant pour connaître la réponse:

« L’éléphant du cirque ne se détache pas parce que, dès tout petit, il a été attaché à un pieu semblable. »

Je fermai les yeux et j’imaginai l’éléphant nouveau-né sans défense, attaché à ce piquet. Je suis sûr qu’à ce moment l’éléphanteau a poussé, tiré et transpiré pour essayer de se libérer, mais que, le piquet étant trop solide pour lui, il n’y est pas arrivé malgré tous ces efforts.

Je l’imaginai qui s’endormait épuisé et, le lendemain, essayait à nouveau, et le surlendemain… et les jours suivants… Jusqu’à ce qu’un jour, un jour terrible pour son histoire, l’animal finisse par accepter son impuissance et se résigner à son sort.

Cet énorme et puissant pachyderme que nous voyons au cirque ne s’échappe pas, le pauvre, parce qu’il croit en être incapable. Il garde le souvenir gravé de l’impuissance qui fut la sienne après sa naissance. Et le pire, c’est que jamais il n’a tenté d’éprouver à nouveau sa force.

C’est ainsi! Nous sommes tous un peu comme l’éléphant du cirque : nous allons de par le monde attachés à des centaines de pieux qui nous retirent une partie de notre liberté.

Nous vivons avec l’idée que « nous ne pouvons pas faire » des tas de choses, pour la simple et bonne raison qu’une fois, il y a bien longtemps, quand nous étions petits, nous avons essayé et n’avons pas réussi.

Un cuento por el escritor argentino Jorge Bucay.

The psychology of color sure is an interesting topic to learn about when trying to gasp how design affects your marketing strategies. And it is not just about web design we are talking about, but the choice of colors could affect the impact your product has over its target audience. From choosing the right color scheme for your product, from branding, the product itself (if edible, think about food products targeted to kids for example)  or the colors used in the website that promotes the products. And that could be a critical phase for your product or service. If your only marketing alternative is online marketing, you don't want your prospect target audience to flee as soon as they glance at your welcome page or keep scrolling down their facebook home after passing your add.

Over at Entrepreneur Gregory Ciotti writes about how our usage of color strategies can help us to create content that persuades people to act. Of course it is not going to be as magical as if you were manipulating your costumers, but you could get close to it. As Gregory Ciotti puts it, is is not about triggering a reaction into people's minds, but rather allowing their subconscious minds to identify what is important, making smart choses about elements colors and how to highlight them over their surroundings. After all, it is not like the same color evokes the same reactions, feelings, or thoughts on every single person. Instead, you focus on how these color patters blend together to trigger the desired reaction into people, from making an attractive product to buy, making it easy for customers to contact you, to bait them into reading an article without trying their sight.

You don't need to be a expertise on the field of design, you only need to know the basics to create your basic common sense on what works and what doesn't. There are multiple sites that try to extensively teach us about the subject and many more that gives us a subtle glance of it. Each of them may help you build your own understanding and strategies on color selection whenever you may need to.

Entrepreneur: The Psychology of Color

Updated: I share with you a related link to an interesting reading about color theory.

http://cmoryl.com/2017/11/26/color-theory/
https://bl1ndf0ld.wordpress.com/2013/04/...fographic/

Interjection are words or sentences that express spontaneous feelings or reactions and they can be either part of another sentence of form stand-alone sentences by themselves. They are one of the major parts of speech, along verbs, nouns, pronouns, conjunctions, etc. Interjections don't need to be grammatically organized inside the sentence and represent Jakobson's emotive function of language, described as words or sentences that "add information about the speaker's internal state", thus its sole purpose is to convey the author's feeling at the moment and are more commonly used in fiction or artistic writing.

Another characteristic of such words or expressions is that they can be disposed of without altering the meaning of the sentence. Some examples:

Quote:Hurray! It is a snow day and school is canceled.
It is so exciting, my goodness, I just can’t believe it.
Joe was late to school and yikes, the teacher was mad.
Oh! I can’t believe how nice you look.
Oops, I dropped the milk and it spilled.

Interjections may be complete sentences by themselves. On these cases you can't directly dispose of them, instead you'll need to replace them completely, some examples include:

Quote:Ouch!
Wow!
Bye!
Oh!
Huh?

Though you can find multiple interjection lists all over the Internet, it may be hard to identify if some words are indeed being used as interjections and their meaning. This was specially the case for me with the word "why", which I use in my introductory title inside my "about me" page. To find out its meaning and usage I had to dig some research, from which I eventually figured out its usage as a way to express surprise. ¡Vaya!, ¿Quien lo hubiera pensado?


Lucky for us, we can find interjections in English as well as in both Spanish (interjecciones) and French (interjections):

Quote:¡Ojalá!
¡Venga!
¡Ay!
¡Oye!

Quote:Hein? (Huh?)
Ouf! (Phew!)
Bon! (Fine!)
Miséricorde! (C'mon!)
Chut! (Shss!)

Now, don't confuse interjections with muletillas, as they are called in Spanish. Though interjections can all be muletillas, not all muletillas apply necessarily as interjections.

That would be all then, uh-oh, see ya!

References:
Wikipedia: Interjection,
Wikipedia: Jakobson's functions of language,
Your Dictionary: What Is An Interjection?,
Espace Francais: Les Interjections

Even if you know you should use two-factor authentication whenever possible, you may be aware that there is also "two-step" authentication. Over at Lifehacker, they explain the difference between both types of extra security methods.

Basically, two-step authentication (2SV / two-step verification) includes any service that make use of, for example, Google Authenticator or SMS codes as additional methods to access to an account. While, on the other side, two-factor authentication (2FA) is any service that requires at least two authentication mechanisms, and where two of those mechanisms fall under different categories with respect to: knowledge factors ("something you know"), possession factors ("something you have"), and inherence factors ("something you are"). Smart cards and USB keys with the FIDO technology would fall into the two-factor authentication mechanisms.

Lifechaker, GrahamCluley