When we first started designing Callionica Conjugations ES, we knew that selecting a Spanish verb from the 3000 we have in the app was going to be very important. It had to be easy and quick for Spanish students to choose the right verb. And our design had to work on the small devices that are so popular for their convenience and simplicity. On iPhone and iPod touch, we have a beautiful screen in a small space so we were very aware of showing only the information you need to accomplish your goals. We also wanted to make sure that you could find the verb you're looking for and select it using only your thumb.

By watching the behavior of Spanish learners, it was immediately apparent that we needed to make it easy to look up a Spanish verb using an inflected form. Many apps and dictionaries only allow you to find a verb using the infinitive, but this can make it hard to find the verb you need. Irregular Spanish verbs can have inflected forms that are very different from their infinitives (consider irgáis-erguir, ve-ir, and fui-ser for example). And some Spanish verbs with similar infinitives to other verbs can have similar inflected forms. We needed to make it easy for you to home in on the right verb even if the Spanish verb you're looking for is irregular or similar to another verb.

We knew that we wanted to show both inflected forms and infinitives in the verb list to overcome both of these problems, so we came up with a verb picker that uses two columns. The column on the left shows inflected forms and the column on the right shows the corresponding infinitive. At first, we tried showing each inflected form as a separate row. This meant we could show forms for erguir among forms for ir for example. Success!

But with over 170,000 inflected forms in Callionica Conjugations ES, the list was unwieldy and hard to navigate using only a thumb. Although some Spanish verbs are similar to others and some very important Spanish verbs are irregular, most Spanish verbs are not. Displaying so many forms in the list meant a lot of scrolling and a large amount of vertical space being taken up by each verb. And it meant that we couldn't show multiple verbs next to each other on the same screen. If you can see multiple similar verbs at the same time, it helps you make sure you're picking the right verb.

To achieve the perfect balance we came up with a solution that minimizes scrolling while still allowing you to see the inflected forms: we condensed multiple rows into a single row for each section of the list where the infinitive was the same. Instead of showing a single form in the left column, we show you two forms representing the start and end of the alphabetic range covered by that row. By doing this we kept the ability to show inflected forms while gaining the ability to show different verbs next to each other on the same screen. As a result, we reduced the number of items in the list from 170,000 to around 5,000 making scrolling much more efficient.

Scrolling and tapping to select a verb from a list is not always the most efficient option. We wanted to make it easy for you to type what you're looking for directly, so we also enabled keyboard input. We provided a toolbar button to display the verb list without the keyboard showing (since the keyboard reduces the visible space for the list) and added a text box at the top of the list for direct entry. Tapping on the text box displays both the list and the keyboard, so you can use a combination of approaches to select the verb. Changing the text in the text box scrolls the list to the relevant point and highlights the infinitive that will be selected when you tap Go.

Streamlining keyboard input involved its own set of design challenges. Although iOS makes it relatively easy to enter accented characters even on an English language keyboard, we wanted to make it unnecessary to provide diacritics in most cases. We decided that sorting and searching the Spanish verbs using an approach that would tolerate missing or incorrect accents would make Conjugations ES even easier to use. So we sort verbs following alphabetical sorting rules for English with the addition that accented letters appear with, but after, non-accented letters.

This means that if you type text without accents, we'll match the accented forms anyway. And if there happen to be both accented and unaccented forms, you'll see them right next to each other in the list. We'll match accents if you type them or we'll show you the best match if you don't.

Note that the verb list is not sorted according to Spanish alphabetic rules. In Spanish, the letter Ñ is sorted as a separate letter - it's not treated as a variant of N. In the verb list, we treat Ñ as a variant of N so that you can find verbs that use this letter more easily.

We also made sure that using the keyboard wouldn't prevent full use of the list. In addition to providing a toolbar button to display the list without showing the keyboard, you can also dismiss the keyboard without losing your place in the verb list. If you scroll the list while the keyboard is showing, we'll hide the keyboard to give you more screen space for the verb list. You can scroll to the top of the verb list by tapping on the status bar at the top of the screen regardless of whether the keyboard is visible or not.

We started with a clear set of requirements for how Callionica Conjugations ES can help you find the right Spanish verb and we followed the design goals to create a user interface that makes it simple and fast to find the Spanish verb you're looking for. We hope you like it.