That 'nuachtán' sounds so foreign to an English speaker. Such a different language!
ia and ua are pronounced "eea" and "ooa". ao and ae are (very roughly) "wee" and "weh".
ái, éi, í, ói, úi, are said the same as á, éa, ío, ó, ú.
The i at the end means the consonant afterwards is "slender" - with a very slight (consonant) "y" sound afterwards. o is used in io to cancel the softening effect that i has. léim is "lehmʸ". liom is "lim". é never occurs before a consonant: it must be either éa or éi.
These can all occur as short vowels (no accent) except for éa and úi, which represent different sounds without the accent.
eá, é, í, eo, iú, are roughly "yaa", "eh", "ee", "yoh", "yoo" as opposed to á, ae, uí, ó, ú ("aa", "weh", "wee" "oh" "oo").
The "e" and "i" mark the consonants in front as slender. You automatically soften consonants before "e" and "i" in English (but probably don't notice it), so I haven't written "yeh" or "yee".
To "unsoften" these sounds, you say a sort-of "w" sound before "ae" and "uí", but without rounding your lips. Gaeilge is something like "gwehlgʸa".
These can all occur as short vowels except eo and ae
You can also get eai, aei, aío, iúi, etc. but you can work these out quite easily if you bear in mind that the final i /o only affects the next consonant.
I still don't understand why it won't let me use progressive tense - "I am reading the newspaper". It's so unnatural to use the simple present - in this case I would even read it as past tense, pronouncing the verb as "red". Irish doesn't even have a progressive tense, so why not let me equate them?
léigh mé an nuachtán -past tense - "I read (pronounced red) the newspaper"
léim an nuachtán - present tense - "I read (pronounced reed) the newspaper"
Because the written English sentence is ambiguous, both the past and present tense sentences in Irish should be accepted, but the present tense is the default, because this exercise occurs before the past tense is introduced.
The present tense form of léigh is léann. First person present tense verbs take a synthetic form where (a)im replaces the (e)ann ending, so the synthetic form of léann mé is léim.
While that looks like the imperative of the verb léim - "jump", and, because you can't lenite a word that starts with l, so the past tense of that verb is also léim, léim an nuachtán is far more likely to be "I read (present tense) the newspaper" than "The newspaper jumped".
Note that you might also be confused by the fact that, in English, "read" (pronounced reed) is spelled exactly the same way as "read" (pronounced red), even though one is present tense, and the other is past tense.